Another blown amp channel. Probably the last one for a while - I plan to concentrate more on troubleshooting and safety related stuff for the time being.
Thanks for your feedback. That’s what I initially do, I measured the voltages at the CB703 connector: -11.7(12), +11.7 (+12), +11.5(12), 5(5), 23.1(25) and -23.3(25). The problem doesn’t seem to be here. Moreover, I checked the voltages at D18 (SMD), that is going to pin 35 (IC21) and is exactly 1.2V, as in schematics. While I am not sure I will get to the bottom of this, your explanations are very helpful (I enjoy more learning something new, rather than having this repaired).
Very helpful (especially the trick with the double ended polarized AC cord - never heard of that before)! I don’t have a variac, but I’ll use the light bulb. You are right though; besides the fuse might have been blown by now, if it were an over-current issue. I will start measuring, but even if I am not able to figure out what’s going on, I still learned something. Thank you!
Great video, My yamaha RX- V640 shutdown right after i press power button.I hear a click then the screen comes on and it goes back off.After it shuts down i see DC offset on the emitter resistors.What are should i check for that kind of behavior?
Hi mark I have a Yamaha RX-V396 5.1 channel receiver that previously had water damage to the main left channel. So I took out the shorted output transistors and driver transistors not sure if the drivers were bad but the outputs were shorted. The amp powered up and gave me sound out of the rear channels and the center channel. So to fix the main left channel I took working parts from the center channel to replace the Output transistors (Q216A/B) the driver transistors (Q201, Q203) the melted 330 ohm resistor (R214) and I also had to replace a blown 47uf 50V cap (C203). Also the .22x2 (R239) ohm resistors was open on one side so I replaced that also. There were also the 2 zener diodes (D221, D06) for the speaker protection relay that were bad so I also took that from the center channel as well. I also took the relay out of the center channel because I took away the protection diodes. Now the reason I did this is because I’m cheap and I want to know what parts I need to fix this channel before I order them. However it goes into high current shut down as soon as you push the power button display doesn’t even have time to turn on everything ohms out ok nothing is shorted even all the other channels ohm out ok. Any ideas I’m going crazy trying to figure this out. Thanks
+101computerman Got it working as it turns out even though the bias transistor whitch ohmed out ok in the blown channel when I took the heat sink off to change it I found it has split in 2 now it’s time to order replacement parts for the center channel
Hi Mark. I have a RX-v661 that goes in to protection mode. By the help of the service manual and your videos I have managed to narrow the problem down. The DIGA menu tells me that it's PS2 Low that is the course of the protection mode. Now I have measured all the PS2 voltages (+12, -12, +5V, +5D, +5I & +3.3D) and they are all fine except one :) When measuring the +12V at connector W100A I only get around 1.52V between pin 2(E) and pin11 (+12). I then measured the input to the +12v regulator (IC104) and that show +22V, so that seams okay. Now if I remove the cable that go from the MAIN2 board to the DSP board the output of IC104 increase to around 5 volts, but nowhere near the +12V that it's supposed to be. The IC104 don't get hot, and there are no signs of overheating in that area of the MAIN2 board Do you have any suggestions? Should I focus on the +12V regulator, and try and replace that, or is it more likely that the problem lies hidden somewhere else?
Thanks for your reply. Assuming that there are some faulty and shorted circuits already, and since voltages are maintained, does that mean that the risk to fry/damage (even more) some components is increased, due to longer exposure to high current?
Hello Mr. Mark I have a Yamaha rxv459, who hand lights up and running (i listen radio to MD/OUT in other amplifier), but is not output to any audio channel. You can help with;
Hi... I have this receiver. I haven't used it for the last few years due to house reno.... Today I hooked it back up today and was listening to it for about 45 mins. When I moved the receiver into the stand the front speakers and the rear speakers stopped working..... the center channel and sub are still working. I've been thinking I pushed a button or something..... Now 2 hours later and I've tried every setting.... I'm guessing this might be internal.... any thoughts?
Update 3. Things changed. Now the bulb lights intensely (pulsating, rather) when connecting to AC outlet; in addition, power transistor Q716C (NPN) does not look good (when measured in circuit). Not sure if this is a new problem or, this was the issue all along. Question: if I remove the 2 power transistors from this channel, and restart the receiver, would that work? I want to check if the receiver starts without entering in protection, with that pair removed.
Thanks! Yes, HDMI indicator did light up when it got the signal (when i used the selector). So that is good to know. Any idea how much say IC1 should cost, or in general, to repair something like that? (Not that I want to replace it myself - a cap or a resistor, I can handle. Not a chip).
I have a Harman Kardon AVR 354 receiver I repaired (replaced L7915) that worked very nice. I didn’t use it for a few months, and then when I plugged it in and turned on, acted strangely. The unit’s front panel lighted up completely (all characters were on). After reset, it functioned “normal” but with repeated (every minute or so) sound dropouts (short, 1s or so). Strangely, during the sound dropouts the front panel blacks out, as if the unit loses power (the power on led is on though), but then comes back and functions well for a little while. In the end (~10 minutes) the sound drops off completely (but the unit stays on, and the front panel working OK), or turns into a whistle. This happens in all sound modes, all inputs, with or without any external connections (even with no speakers - reacts the same, you can tell that from the front panel blackout). Between the sound/display dropouts it functions completely “normal”. I tried repeated resets, doesn’t change anything. The F110, F111 fuses and wire (jumper) from HDMI board to Regulator board upgrades have been addressed by the previous owner. I didn’t see anything similar on Internet, have you encountered this issue before?
I have a Yamaha htr 5440 receiver and no channels were blown blown channels are usually caused by wiring your speakers at too low of an impedance like if the impedance is lower than what the receiver is able to handle
Hi Mark, Yamaha RX-V795a. Shuts off after 0.5 sec. Diagnostic mode quickly (0.5s) shows: "PS PRT 39%". Output transistors (C3856 / A1492 pairs) look OK in circuit. The Noble resistors look OK. The regulator 7812 (x2), 7912 and 7805 (all on the main heatsink) have the proper voltage. Mind you, I only have 0.5 sec to do the measurements. Is there any way to increase this time? I can’t measure the DC offset, too short a time.
the unit work perfectly, if i wait some seconds between power on/standby operaton. if this is a normal operation, i'll go close the cover of the unit. Thanks for your help, and before i forget, nice videos (but a little dangerous for curious people) you posted. Sorry about any errors in text. see ya.
i have a kenwood that was turning its self on and off but would still work now it wont come on the main relay clicks rapidly and has blue flash in it you think it could be the transistors?
Great video posts, Mark. I have an RX-V667 that is tripping circuit protection on DC after a lightening strike. All values in the diagnostic menu are normal except for P1-1 (DC_PRT on IC902) showing value 0 instead of normal 32 to 74. Is there a place to start before looking at each amp channel?
***** Start the receiver in protection cancel mode and see if there is a DC offset on one or more channels. DC on one channels obviously means that channels needs repair. More than one is a power supply problem of some sort, or there could be a problem involving Q1072 (not) providing a -12.6 volt bias to all amp channels.
hi i had a question how would i fix my ir sensor on my harman kardon avr 40 i bought a new remote for it but the receiver isnt working with the remote and the remote works good.
Have the same receiver - and I think a lightning surge took out my HDMI circuits. It turns on, but seems like no signal is coming out of either channel. Do you know what it would take to fix this?
Thanks mdzacharias i open my receiver and fixed a broke fan and change two fuse thant blown going to try your advice two questions though when i unplug the hdmi board the receiver does not shut off clicks on and then off over and over but the power does not blow is it possible its bad caps on hdmi boards like the other onkyo's. One more question i have seen your reviews of the multimeters can you recommend a good starter meter on the cheaper side that can handle voltages of a audio receiver
Update2. I tracked the high voltage, back to transistor Q708 (NPN, C2240). I replaced it, and now the readings at the Q716C (NPN power transistor RL) are much closer to the schematics: the transistor base reading changed from 6.2 V to 0.47 (0.4 on schematics). Unfortunately the symptoms are identical, and the display still shows the same PS PRT 39%. Other voltages are OK, no DC offset… I wonder if I can reset the unit, but how, since the display is gone in 0.5 sec. I guess I am stuck.
@costellom5 You mean the desoldering braid? Pretty common in my work. I also was using a spring loaded solder removal pump, if I recall. I don't use that so much these days - too easy to mess up the solder pads.
I found the can that blew off the cap down in the receiver and it reads 16v4uf. They didn't have that at radio shack. Will a more common one do? The cap was in that assembly that screws to the heat sink above the stuff you are working on and has two 5 or 6 lead cables coming off it. Also wondering what soldering iron and vac you are using. Thanks, Scott
Scott Young You can solder in a 4.7uF at 16 or 25 volts. Cut the leads fairly short and first solder the original circuit board pads a little, then tin the capacitor leads with solder. You should be able to use the soldering iron to then solder the leads to the board. Be sure to observe polarity of the cap. The old solder station was a junk MCM model and it died. I went back to using my old Weller station. The other device you may have seen is a Denon Instruments desoldering tool. I don't use it much anymore; a friend gave me a hot-air gun with a pinpoint nozzle attachment. Don't know the brand.
goodmorning, mark, i have a yamaha rxv 661 and sometime ago i was playing a CD i had just gotten whilst i was in the yard. unknown to me the CD was recorded high and so when i heard the volume came up i ran to lower it but was too l8t. the reciever just shut down n i waited a few minutes then turned back on i saw the display but shortly after the power just went back off i tried it again this time all i heard was TWO CLICKS. what do u think is my problem and can it be fixed?
I think you need to look at the PRV line on the Main (2) board. It's the board along the top of the heat sink, so you should be able to get to stuff pretty easy. The PRV line sums all the power supply lines and provides an error voltage for the microprocessor. This winds up over at IC21 pin 35. Occasionally the backup capacitor C103 might leak and give false trigger on the micro but usually just a bad regulator over on Main (2).
Hello mark i have a rx v373 with Dc prt 255 hi error can you please guide me where to start checking for faulty components. I know this video has been uploaded from 8 years but hope you still can help me thank you in advance
i have a yamaha rx v1900 av receiver,both right and left channels were shorted out destroying four power transistors,four driver transistors,two 5.1v zener diodes,two 220 ohms resistors,also one of the power supplies were damaged that supply the main amp board with a dual plus and minus 61 volts,this has been repaired but the main amp board is dragging the dual supply down very low,i cannot find any more shorts on the main amp board that may be causing this problem,can you please advise me.
Ok, I can't quit. So I checked the noble resistor and it is bad. I going to replace those two transistors also 'cause they are so cheap and apparently go bad. But can you say how to mimic that noble dual emitter with p/n mcm 28-0520 (since that part not available)?
Scott Young You might want to double check that resistor - they rarely go bad on the Yamaha's. If the outputs are bad I guarantee the drivers are bad, and probably the 5.1volt zener diode as well. Also the 100 ohm resistor that sits between the emitters of the drivers should be checked. I haven't seen dual .22 ohm 5 watt resistors on eBay. If it's really bad, usually only 1/2 is bad and the other half could be bypassed with a single. If you're in the U.S. B&D Enterprises would have the dual, I'm sure. I have a drawer full of the things at work. They're really common if you work on these things. Many of those I have are pulled from scrappers.
Hi mdzacharias, I have got RX-V630 which turns on for a brief moment and shuts down. Sometimes there is message check SP wire on start. I have disconnected all my speakers but still the problem remains. Can you guide me on where the problem would be or have you got a circuit diagram for it?
Thnx mark for the reply. The technician guy had connected A TERMINAL rights posts to the right spkrs and left to the left speakers, same way he had done with the FRONT B and assigned as extra presence. I tried the B TERMINALS right & left to one speaker and done with the other spkr too. It sounds grt. But the front A TERMINALS doesn't give any sound output whn connected the same way.
Hi Mark, I have a Yamaha RXV 661 Receiver and the Polk Rtia 3 connected to it via the front A and front B/ zone 2 with extra SP assign mode. It only plays the LEFT SPKRS woofer & RIGHT SPKRS tweeter. Can u pls throw light on the issue as I am not able to know work it out.
Update. Using the trick you mentioned before, I was able to take some measurements. I also used the light bulb as a precaution. It lights up a bit when connected to the power outlet for a second, and them dims out, so no over current issues, as predicted. The rear L power transistor Q716C (NPN) has 6.32 V at the base (should have been 0.4), 0 at source (OK) and 38.5 (40 on schematics) at collector...continued
@ mark zacharias .Do you repair these receivers for the public. I have a Yamaha RX-v665 that I believe may have been damaged from a lightning surge. Having trouble trying to find someone near me who can repair it.
I'm not really wanting to deal with shipping and receiving and all that; and besides, lightning can be pretty devastating, often unrepairable. What is the receiver doing wrong? And are you sure it was lightning?
Thank you for your reply mark.I checked the mute drive circuit and one diode D12 reads 14v on both sides so i de soldered it on one side and the eq works fine now.maby a faulty cap or transistor.I'll keep checking.
Hey mark love thank you for this video I have the exact issue with my v661 I have done changed the output transistors but am struggling with the other repairs like the driver transistor I need assistance with the range it should read when tested normally and furthermore. I would like to if possible repair as I would hate to see it end as land fill. Any help would be grateful.
+Andrew Shorter If the outputs were bad ASSUME the drivers are bad, also the 5.1 volt zener diode. Also check the resistor between the emitters of the driver transistors. After these parts replaced, check resistance from base to base of the output transistors and compare to other channels(s).
Hi, i have an amplifier which hv the label on the motherboard for the capacitor to be 2200uF 35V. However, the manufacture put 1000uF 35V caps in it. can i replace it wh the 2200uF 35V caps instead according to the board?
Hey Mark, My RX-V661 turns on and has a display for about a second then shuts itself right off. Any help? It does not go into protection mode, I also checked the channels and they all appear to be good. So I'm at a loss?
You need to check the output of all the fixed voltage regulators on the Main (2) board mounted higher up on the main heat sink. Also the outputs of Q1045 and Q1046 (plus and minus 59 volts approx) and Q1000 (about -12.6 volts) . In order to facilitate troubleshooting problems not involving a blown channel or hard shorts, there is a protection cancel feature in the diagnostic menu. While pressing and holding "straight" and "audio select" press the Master power button and continue to press the first two until the SLEEP indicator flashes on the display. You can then troubleshoot the DC voltage problems at your leisure. If you have any technical skills and a decent multimeter anyway...
Hi Mark. I have been looking though your videos seeing if you have encountered my problem. I have a Yamaha RX-V667 receiver. It was working fine until recently it started constantly switching DSP modes. Its happening intermittently. I some of the other buttons on the front are also activating. Is it possible just to replace the front panel? Where could the replacement part be ordered?
pvdeluca Kind of unusual problem. The front panel switches are part of a couple of resistive networks. Any leakage could trigger this. Like if some liquid got in there somehow, maybe causing some corrosion. Tact switches can also be leaky but this is less likely. The part number for the front board is WU427500 for the U.S. model only. Ending in 600 or 700 for other markets. Probably fairly expensive.
Mark Zacharias Hey thanks for the response. Ive googed for days to find someone with the same problem. My apartment is very humid so this might have caused the issue. Too bad it was a great amp. It would feel like such a waste if i didn't get this repaired.
Thanks going to try to check those things hopefully but the receiver stays on when i turn it up but past 44 - 45 the sound cuts off not the receiver but im guessing its the same problem
+Brian Wallace I would need to know a whole lot more. I'm guessing you may be out of your league here. A person with any technical ability would have already given me the relevant information.
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In the diagnosis mode of Yamaha htr 6030 a message for a very short time "PVR PRT 59"is displayed and the receiver shuts down. What does it mean and where does the fault lie? It definitely means power supply issue but what does the number 59 signify ?
Indicates a power supply problem. There is a Protection Cancel mode that will allow you to keep the unit ON while you troubleshoot. email me at mark_zacharias@sbcglobal.net and I can email you the service manual. Most likely a bad voltage regulator IC like a 7812, 7912, etc.
i have a yamaha rx-v367 that when i push the power button it clicks like its coming on then clicks off. please help me figure out what it could be id love to send her to you shes been my reciever for over 10 years and this is the first problem ive had from it.
Mark, I have a Yamaha RX-V2090 that I bought new (for $1549!) somewhere around 1996. It has been a great unit, but over the years has lost some of the channels for the speaker outputs. I have downloaded the service manual, I opened up the case tonight, and am looking for obvious signs, like discolored boards, but am not quite sure where to begin testing. Any advice on where to start? Thank you!
Mark Zacharias Thanks for the reply. I have figured out how to get it in diagnostic mode, but it seems some of my buttons are sticking. For example, if I push "Tape 1", the "Tape 2 Monitor" comes up. It seems a few of the buttons are mixed up with the one next to it. I do have the remote, but has the same issues. I'm not too surprised for an 18 year old unit. What can I use to clean them up with? Can I contact you off of youtube? I may have a lot of questions, if you are willing to help... Thanks!
I was able to take the remote apart and clean it. It appeared someone (besides me) poured a few cans of Pepsi inside. I just (carefully) used soap and water to clean the contact side and the button 'sheet'. It has never looked so good! Would something like rubbing alcohol also have worked on this, and/or the receiver?
Mark, I have a RXV-665 that has the STK443-130 amps....The unit had a similar problem,shutdown and I can get the self diagnostic to read - DC PRT :075H Do you have any experience or tips on this model,,? Thanks, Steve
Just curious if you've run into the same issue with a rx-v795a Yamaha and if it could possibly be the same fix? Seems like every blog I've read says something different. Relay clicks but no power. Thanks and good work!
+Justin Bergendahl The most common thing is a blown amp channel caused by bad solder connections at the bias transistors. I would check continuity of the main power transformer first. If the unit went out after playing too loud for too long, the transformer could be bad. You need some skills like soldering and know how to use a multimeter or you're probably out of your depth on this one.
+Mark Zacharias well I changed the relay on the main power thinking it was the problem but still getting the issue. Main transformer has 120v. The aux outlets work without power on. It has to be within the amp or a capacitor dried out. You obviously deal with these a lot. Just trying to narrow it down. All help is much appreciated
+Justin Bergendahl You should check continuity or the primary winding of the main power transformer.Should read a very low DC resistance. UNPLUG from the wall first! Next check for emitter-collector shorts on the output transistors. The smaller amp board amp channel nearest the rear of the unit is most common.
Hi Mark, My Yamaha RXV661 which was running fine for the last 4 years suddently refused to turn on. I was trying to plug and unplug a few devices from the same power plug when I found the 2 of the SCENE button LED turn on for a while. Thereafter, the device simply refuses to turn on. Checked the fuse out of common sense, but they seem ok. What could have gone wrong. Will appreciate your inputs Mark.
I got that last part in fixed that but my sound still cuts out at about 45 or so and was able to stay on for a few seconds at a higher volume i am not sure seems like something with the front cover because it did stay on at almost max volume. But it still says check speaker wire for the first 10 seconds when i first power on the unit after plugging it in to the wall for the first time.
I am bit familiar with electronics. I checked all C4468 and A1695 transistors with DMM, could not find any shorted ones. I have not checked at resistors and diode yet.
Scott Young Caps are very rarely bad in a situation like this. A blown channel can be just a couple output transistors and nothing else - it it can be almost total destruction of the board and a large number of components destroyed, or anywhere in between. Some people think that "90% of problems are caused by bad caps". This is total bullshit. There were batches of bad caps affecting flat screens and computer motherboards a few years ago. Other cap failures are generally very random, unless they are caused to be bad by other factors - heat, over voltage etc.
Hi Mark, I have a RX V477 working on, its brand new, got off Ebay, in protect mode. Got into the diagnostic mode, first of all I don't understand what all that stuff means in diagnostic mode, so far I pulled and replaced all the output transistors, I had already bought all 10 anyway, but the old ones checked fine as did the emitter resistors, I'm new to electronics, went to school and trying out a few of these bad stereos to get some experience. What I need is a schematic of the power amp section, can't find it for purchase or free. And something about how the fault mode codes work. Apparently I have some other bad items in there I failed to check. BTW in fault mode I seem to have one dead front channel. Good learning experience!! Thanks for the help. Subscribed!!
+Vernon Bosshard This vid cleared up a lot of confusion, so much crap on the net about why units go into protect mode, but from what I read is its always due to DC offset on the power transistors or something to do with the power amp section causing a fault. I bought a few units off Ebay for practice, got a Sony and found the schematic online. What size resistor do you use as a Cap bleed off?
+Vernon Bosshard I often use a 750 ohm 20 watt resistor to bleed of the higher voltages, especially if the voltage on a particular unit doesn't bleed off by itself. Lower voltages sometimes I'll use a larger eight ohm resistor because it bleeds off faster.
I have Pioneer VSX921, suddenly notices there is not audio from SBR and SR channel; I checked that there is audio at relay PIN. Other channels are working fine. could it be a problem with relay? any logic that is not turning relay on. Thanks in advance
Thanks a lot Mark. I also had doubt about the relays. I did reset and there was no luck. Then I checked a capacitor leg after relay RLY6 and found audio. Now I can surely say that the problem is with track or the speaker pin solder joint. Accidentally I pushed the speaker socket and it worked! It is a loose fault or dry solder problem. Since opening the whole circuit board I made a jumper about half an inch from capacitor leg speaker tag. It’s now working fine. Thanks again for your reply.
hi . i repaired a yamaha htr-n5060 with a power supply fault. The fault was a 22nf capacitor in the power supply. It still has fault in memory stored. I see it in the diag menu . I goto menu 9 facotry reset but i don't know how to clear the fault (factory reset) . what button on receiver do i press to confirm factory reset? when turning on receiver it is shutting down because stored fault? Or is there still a fault somewhere? thanks
On a Yamaha, each menu selection in the service menu has the main selection and a sub-menu selected by one or two other buttons. In the reset portion of the menu, you must select the reset, then just turn the unit off. The reset will be effective at next power-up.
• Operation procedure of DIAG menu and SUB-MENU There are 23 MENU items, each of which has some SUBMENU items. DIAG menu selection Main unit: Select the menu using the PROGRAM knob (RXN600/ RX-N600D/DSP-N600 models) or (Forward) and (Reverse) keys of PROGRAM (HTR-N5060 model). SUB-MENU selection Main unit: Select the sub-menu using (Forward) and (Reverse) keys of PRESET/TUNING.
@@mdzacharias thanks . when i reset. it is still going into protection. when i goto menu nr. 20 there is p1prt 032 stored. in the service manual i read. i understand thay value 17 to 66 is normal. so 032 is normal? PS1/PS2 (Power supply voltage protection detection) Power supply voltage protection value (Normal value: PS1: 17 to 66, PS2: 36 to 53) PS1: Detects +5S and +5DAB does this mean there is still a problem in the power supply or in +5S and +5DAB ? this are voltage regulators? thanks.
ive not bolted back the main amp board to the heatsink and ive disconnected the thick power wires from the collectors of the power transistors cause ive already had 4 more power and driver transistors go short on me cause of a fault with the plus and minus 61 volt driver supplies,there seems to be something on the main amp board causing the dual supply to be very low,im having to run the amp in diagnostic mode so i can test but i dont know what else to do and yamaha uk are very unhelpful.
Wierd i was able to get audio when turning it on just now but when i pluged in the fm antenna it shut back off. There is a fan inside that is not working does that cause the receiver to power off like that its 120mm fan was going to replace it
Hi i have a Yamaha RX V667 and only had about 1 year from someone who never used it now the Power Transformer was all new looking silver on top through the vent but just noticed that there is browning on the top which looks like har syrup sitting on the top. Is that due to the heat over the time that has turned the coating Brown ??
Mark Chancellor I've seen stuff like this from new. Looks like a resin coating. Otherwise someone might have spilled something. If the receiver works I don't think I'd worry about it.
Mark Zacharias Hi thanks for the advice it must be a resin if someon spilled something then the heat generated will cause a burning smell. Cheers keep up the good work
Hey Mark, that is a great and very useful video! I have a Yamaha RX-V550 reciver, and it works perfectly, but sometimes it shuts down with loud boom when I switch between output programs (2CH, 6CH, Dolby Digital, etc.). The other problem is: when I plug in a headphone jack it works well only in 2CH mode. In other mode I hear only distotred music. When I pull out the headphone jack in 6CH mode, the receiver shuts down immediately. I checked the protection codes in the Diag Menu, I found only this: DC PRT 14 C Can you help me, what can I do with this reciver? Thanks! Peter
This type of thing could be caused by a bad muting transistor, if only on one channel, or a loss or a DC bias voltage like "-12 AMP" from Q253 on the main board. You can power up the receiver in"protection cancel mode, described on page 23, but if the problem is intermittent you might be waiting a while to get any results.
I would definitely be looking at the power supplies, like plus and minus 15 volt (maybe + or - 12 volt) lines, also any muting circuit that may be used.
So I have this same receiver, rx-v661 which works fine, however the display no longer works. Tech seemed to think it was a problem with the power supply. Any ideas on that? If so do you know where I could get the parts to replace and fix it? Great video by the way
Nice work, I have a yamaha rx-v667 and it works great but i have trouble getting radio stations to come in. after looking it over i see the antenna plug is bent up kind of funny and I'm thinking this might be a bad connection. would this be easy to fix? Should I take it to a shop? I have done some soldering before but wanted to ask. thank you.
dankbobby The tuner is a complete module and fairly easy top replace except it is situated kind of underneath the HDMI board. The part number is WQ756600. List price is about 40.00
Yeah your right about that,I went to turn on the amp and i heard a loud snap and flash..I thought the transformer went,but it was the circuit lifting up from the board soldered it tested it same thing so i put a jumper on it.the yamaha RX-V2500's fan circuit is still not working so i improvised it with it's own power supply Until i can order a new board.I know yes i am an amateur,but thank you for your informative video's.
If the bias transistor is bad I would recommend ordering the Yamaha part number, VK432900. You might be able to get away with a 2SC2603, but the problem is the bias would probably be somewhat at variance with the other channels, and there is no real adjustment provided.
Hi Mark. I have a Yamaha RX V659 that immediately goes into protection mode. The error code is dc prt 026 hi. There is no short found on the output transistors. Any suggestions? Thank you.
@@IIWII9 DC PRT indicates a DC offset on one or more amplifier channels. If the problem is on one channel only the likely culprits are the differential transistor pair or the low frequency roll-off capacitor for that channel. You can email me at mark_zacharias@sbcglobal.net
Hi Mark, I have a RX-V771 and it goes to protection mode few seconds after power i powered it up. No standby power light when its off also. When i do the self diagnostics, it shows PS2 PRT: 186H. As per manual, this error is caused by abnormal voltage reading in -VP, +5A, +5T and 3.3s but this voltages are present and normal as per my checking. The other vital voltages on the AVR are present too. any idea what is wrong here? Thanks in advance
hi +Mark Zacharias, unfortunately all the voltages, (+12, -12, +18, +5, amp dc power and other relevant voltages) are ok. any other hint? any option to trick/cheat/bypass this error ? thanks
Well something is triggering it. The PS PRT line is comprised of summing resistors wich go to each of the monitored voltage lines. The center point where they tie together is the PS PRT line. Occasionally a resistor is bad, but more often you just have to find the high, low or missing voltage source. There's no trick to make it work in spite of the protection problem, except the protection cancel part of the diagnostic menu, which only works so long as it's in diagnostic mode.
Nice video! I have one of these that just came in our store and the owner said they were listening to it LOUD and it went off and now when you hit the power button there is nothing. Any ideas? Think it is fixable?
Hi mark, Im looking for some help if could please. I got a Yamaha RX-V367 which shuts down when I raise the volume, for recommendation of the troubleshooting book I change the cables and the problem still happening, also I check every single speaker separately and the receiver still shuts down. Can you tell me what can I do or what sort of circuit can I change from the internal panel. Thank you so much for your time.
Wilson Bastidas There's at least a couple things that could cause this. Perhaps a bad output IC, for example. A severely clipped waveform is interpreted by the microprocessor as a DC offset. A DC drift arriving at the input of one of the output IC's could case this, but it's unlikely. Bad solder connections at an output IC could cause this also. You should disconnect all speaker wires from the back of the receiver and see if it still shuts down with increased volume. That would be useful information.
Hi Mark, Happy new year 2015, txn for your answer, well I disconnect al speakers and the receiver doesn't shut down which mean the problem can be made from the speakers. do am I alright?
hi mark will you please let me know how my hdmi problem fix RX-V465 video is yellow and all wires is good I checked so what might the problem should I check the regulator volt and capacitor please suggestion me
abhisek bhandari Normally in this situation the HDMI (Digital) board need to be replaced. Too expensive. If you are very good at working with surface-mounted IC's you could try replacing IC7 on that board. It is an SIL9134CTU 100-pin surface-mount IC.
No, it would not reset. There is a temperature sensing IC on the regulated power supply board. Possibly defective or maybe bad solder in the general area. IC238.
Hi Mark i have a rx-v3900 it powers on but no sound from any channel the AM FM radio or anything input to it and speakers are good use them on other 3900. any ideas thanks
The 3800 and 3900 are probably two of the most difficult models for service - that Yamaha has ever built. Even an experienced technician would have his hands full with this one. Here is a link to the service manual. Good luck. elektrotanya.com/?q=showresult&what=Yamaha%20rx-v3900&kategoria=&kat2=schematics
The trick on these is to prepare a double ended POLARIZED AC cord; Take the receiver's own cord and plug it into one of it's own switched outlets. Take the double ended cord and run it from the the other switched outlet to the AC outlet or variac. The receiver will shut back down but the internal voltages will stay up. Make sure that the AC cords maintain the Neutral and Hot relationship, or BIG SPARKS will occur.
@killerkoop33 I cannot find this model number listed. Not a U.S. model anyway. This could take some real troubleshooting. Are you a technician? The likelihood is either a bad main power transformer or a high-current shutdown, such as might be caused by a blown amp channel.
Hi Mark, My knowledge of electronics is very basic. I have a Yamaha RX-V773. Failed while watching TV - while at normal volume... The red power LED glows dim, no other display visible. Press the on/off button on the remote, the red led flashes dim. The fuse "was" OK, until I tried to do the factory reset to default. As soon as I pressed the button combination on the front panel to attempt the factory reset, there was a big flash as the fuse "went open circuit". With the fuse open circuit and using a couple of different control panel button combinations, the front panel does light up with text and numbers... This proves the front panel still works - but I think that's it - probably nothing useful in the display I do not know if a test I performed proves anything, but connecting my multi meter (set to ohms) across the speaker output connections gives a resistance reading on all channels EXCEPT centre, left surround and right surround. So, that is 3 speaker connections adjacent each other that look bad to me (unless this test is useless of course). Some history - which may have been the beginning of the failure, some months ago, the centre channel started to cut-in and out... I thought the amp was history so I went out and bought a Denon. While performing the unit change over, I found that one of the centre channel speaker wires had come out of the connector =:-( .... Anyway, the Yamaha still worked after re-connection the speaker wire, so I installed it at my holiday house where it worked fine for some weeks, until it failed a few weeks ago while watching TV.... Sorry, not much info, but on this brief description, what is your feeling - trash it or do you think it is worth fixing. Is my output test valid? Thanks Mark, Jim (in AUS)
If it blows the main fuse something is seriously shorted. Yamaha's protection circuits work so fast in the event of a current overload, they usually cut off before a fuse can even blow. Anyway, forget about checking resistance at the speaker terminals for now. Check resistance emitter to collector of the output transistors, focusing first on the channel you were having problems with. If there's no particular issues found there, check for a short from the collector of any NPN output transistor to chassis ground; do the same for any one of the PNP outputs. (each channel's NPN collectors are tied together inside, so are the PNP's) Occasionally there is a bad mica insulator. If this is the case the can also be a carbon path formed from that screw hole in the heat sink, right up through the body of the transistor. In this case the transistor must be replaced along with the mica. Merely trying to clean away the carbon as a fix will not hold - I been stung on that one before.
I had another Yamaha a couple days ago with a similar symptom. One of the main filter capacitors was shorted . Fuse blown - measured dead short from the collectors of (PNP or NPN - I forget which) output transistors to ground.
G'day Mark, thanks for the update. Just wondering if you might be able to point me in the right direction to download a wiring diagram for my RX-V773.... Been searching but not having much luck. Thanks, Jim jim.stapenell@gmail. com
G'day Mark, I did reply to your email address - did you receive my message?..... As it happens, I found a manual online for an RX-V673 which I think is similar to my RX-V773... Anyway, I wonder if you might be able to comment on something I found. My relay does NOT click when the power button is pressed. I unscrewed the board with the relay - fitted clip leads between the ground points on the board and the unit metal frame. I then switched on the power, applied multi meter to measure the voltage between the closely grouped 5v and ground (?) at the 11 pin plug connector - I measured the voltage OK, but when the multi meter leads contacted the 5v & Ground points, the relay clicked. From this info, can you possibly identify any obvious faulty components - or at least group of parts I could replace as a test. I know this request is a long shot but thought I would ask anyway. The reason the relay clicked when I connected the multi meter is probably because I had the board disconnected from the 11 pin plug? Who knows.... Let me know if you did get my email... Thanks Mark, Jim
2SC4027 and 2SA1552 are the replacements I used. 2SC4793 2SA1837 are used by Yamaha in some step-up models. They survive more often if the main output transistors fail.
No, it doesn't. I also visited the local yamaha service center and they said that the DSP PCB has got rusted for whatever reasons. Also gave the faulty PCB part no WJ698200 which needs to be replaced. Now, this PCB is not available in India. Can you suggest where should I get this from.
Hi Mark, Thanks for the clip! Do you have any experience with a RX-V363 receiver which turn off after a short while? Sometimes it will take several seconds to turn off, sometimes a couple of minutes - but it will never keep on working. Thanks!
sblueeye After it has malfunctioned, let's try a diagnostic mode. It will be important to read the display during the first couple seconds. It will read DC PRT followed by a number, or PS PRT, etc.Start the diagnostic mode by pressing and holding "straight" and "audio select" then pressing the standby/on button. The receiver may or may not stay on. Get that initial message and report back to me. If it's a PS PRT message should be relatively easy power supply type problem. DC PRT could be more trouble.
sblueeye Best guess - a bad 7912 voltage regulator IC. Possibly IC 237 on operation (2) pcb. Try to find that -12v line - see if it's missing or way low.
Mark Zacharias Can I tell by checking the -12v if it's the 7912 or one of the 7805? Also, I assume I need to do all that when protection is off, is that correct? Thanks so much for helping!
sblueeye You should be able to check the output of any of the regulators - or anything else you can reach in there - with the unit in Protection Cancel mode. Don't forget - I accept Paypal!
Question, I have a yamaha RX-V373 that just 2 days ago went dead while I was watching it. It will not power on at all. In your opinion is it worth fixing or would I be better off buying a new receiver?
Impossible to say for sure until the troubleshooting is done. The most common problem I have seen with these is a bad amplifier output module. There are two in this model, one is a two-channel version and the other is a three-channel version - hence the five-channel receiver. More often the 3-ch IC goes bad. The protection circuit has the receiver locked to avoid further damage.
Mark Zacharias Hey Mark, I also have a 373 that won't power up. The relay trips when I do the tone control, straight, and power reset. It's a few months out of warranty. No signs of heat damage and fuse is intact. Any ideas where the most likely cause is? No symptoms prior to shutting off. Working one day. Not the next.
Mark, great video! I have a BA in EE but haven't really used anything I learned since I got my new job. I have a Yamaha Rx-v765 that I believe is in high current shut down mode like the one in this video. When I plug it in I hear 3 clicks from the 3 relays but there is no display. I have checked voltage going to the display and it measures close to what the service manual says it should have. Do you happen to have any tips or tricks to verify it is in high current shut down mode or any other tips on where to begin troubleshooting? Part of me says I should just send it in for repair but my inner nerd is telling me I should be able to fix it myself.
These can have a variety of problems. If the main power supply voltages to the output transistors is staying on, then probably not a high current shutdown. Maybe the display circuit - maybe a blown channel. I would start by looking for any shorted output transistors. I can probably send you a pdf of the service manual.
Mark Zacharias I have the service manual but everything I have checked so far seems to be correct. I haven't dug to deep into yet though. I basically just checked a few things I could easily get to like transformer and display board voltage. I was only using the rear speaker outputs at the time it went out as my main speakers are powered. I should also note there is about 56 volts going to the chassis. I will check the output transistors next. I appreciate the reply.
Mark Zacharias None of the output transistors appear to be shorted as far as I can tell. They all have high resistance across collector and emitter. I'm not saying my in circuit transistor testing is 100% percent accurate either though. I may do some more exploring in the display circuit.
Mark, I think I may have found an issue. There is a 25 pin ribbon cable that goes from the main video board to the display circuit. When analyzing the voltages coming out of the video board to the ribbon cable there are several discrepancies. Pin 24 which is labeled 3.3DSP is supposed to be 3.4 but I am reading only 1v. Is that just because of another problem and the microprocessor is telling the display not to turn on or could the processor itself be damaged. I think I maybe getting in over my head here but it is certainly fun. Sorry for hijacking your video.
Jeremy Meyer I have seen things like this cause a "no display" problem. In my case. I replace the digital board, where the 3.3D (for display) is generated. (Seen this twice only)
@killerkoop33 The power transformer usually only goes out if you've been running it really hard for a couple hours.The transformer can be checked by a knowledgeable person. Also Yamaha with a blown channel may pull so much current at turn-on that the protect is triggered instantly, you never even see the display come on. If the transformer is OK this is probably the case. I wouldn't recommend just ordering the transformer til you know it's bad. About 135.00+frt. US model.
Great work! I really enjoy your smooth and calm presentation.
Thanks for your feedback. That’s what I initially do, I measured the voltages at the CB703 connector: -11.7(12), +11.7 (+12), +11.5(12), 5(5), 23.1(25) and -23.3(25). The problem doesn’t seem to be here. Moreover, I checked the voltages at D18 (SMD), that is going to pin 35 (IC21) and is exactly 1.2V, as in schematics. While I am not sure I will get to the bottom of this, your explanations are very helpful (I enjoy more learning something new, rather than having this repaired).
Thanks alot. I love watching your troubleshooting..
Yamaha is just about my favorite. I work on so many because I do factory authorized service and people ship them to me from about a four state area.
Does the power relay click, however briefly, when you press the Main Zone on-off button?
Very helpful (especially the trick with the double ended polarized AC cord - never heard of that before)! I don’t have a variac, but I’ll use the light bulb. You are right though; besides the fuse might have been blown by now, if it were an over-current issue. I will start measuring, but even if I am not able to figure out what’s going on, I still learned something. Thank you!
Great video,
My yamaha RX- V640 shutdown right after i press power button.I hear a click then the screen comes on and it goes back off.After it shuts down i see DC offset on the emitter resistors.What are should i check for that kind of behavior?
Hi mark I have a Yamaha RX-V396 5.1 channel receiver that previously had water damage to the main left channel. So I took out the shorted output transistors and driver transistors not sure if the drivers were bad but the outputs were shorted. The amp powered up and gave me sound out of the rear channels and the center channel. So to fix the main left channel I took working parts from the center channel to replace the Output transistors (Q216A/B) the driver transistors (Q201, Q203) the melted 330 ohm resistor (R214) and I also had to replace a blown 47uf 50V cap (C203). Also the .22x2 (R239) ohm resistors was open on one side so I replaced that also. There were also the 2 zener diodes (D221, D06) for the speaker protection relay that were bad so I also took that from the center channel as well. I also took the relay out of the center channel because I took away the protection diodes. Now the reason I did this is because I’m cheap and I want to know what parts I need to fix this channel before I order them. However it goes into high current shut down as soon as you push the power button display doesn’t even have time to turn on everything ohms out ok nothing is shorted even all the other channels ohm out ok. Any ideas I’m going crazy trying to figure this out. Thanks
+101computerman
Got it working as it turns out even though the bias
transistor whitch ohmed out ok in the blown channel when I took the heat sink off to change it I found it has split in 2 now it’s time to order replacement parts
for the center channel
Hi Mark.
I have a RX-v661 that goes in to protection mode.
By the help of the service manual and your videos I have managed to narrow the problem down.
The DIGA menu tells me that it's PS2 Low that is the course of the protection mode. Now I have measured all the PS2 voltages (+12, -12, +5V, +5D, +5I & +3.3D) and they are all fine except one :)
When measuring the +12V at connector W100A I only get around 1.52V between pin 2(E) and pin11 (+12).
I then measured the input to the +12v regulator (IC104) and that show +22V, so that seams okay.
Now if I remove the cable that go from the MAIN2 board to the DSP board the output of IC104 increase to around 5 volts, but nowhere near the +12V that it's supposed to be.
The IC104 don't get hot, and there are no signs of overheating in that area of the MAIN2 board
Do you have any suggestions? Should I focus on the +12V regulator, and try and replace that, or is it more likely that the problem lies hidden somewhere else?
Yeah - replace the +12 volt regulator and you should be fine. Good job!
Great work as always....
Thanks for your reply. Assuming that there are some faulty and shorted circuits already, and since voltages are maintained, does that mean that the risk to fry/damage (even more) some components is increased, due to longer exposure to high current?
Hello Mr. Mark
I have a Yamaha rxv459, who hand lights up and running (i listen radio to MD/OUT in other amplifier), but is not output to any audio channel. You can help with;
Hi... I have this receiver. I haven't used it for the last few years due to house reno.... Today I hooked it back up today and was listening to it for about 45 mins. When I moved the receiver into the stand the front speakers and the rear speakers stopped working..... the center channel and sub are still working. I've been thinking I pushed a button or something..... Now 2 hours later and I've tried every setting.... I'm guessing this might be internal.... any thoughts?
Update 3. Things changed. Now the bulb lights intensely (pulsating, rather) when connecting to AC outlet; in addition, power transistor Q716C (NPN) does not look good (when measured in circuit). Not sure if this is a new problem or, this was the issue all along. Question: if I remove the 2 power transistors from this channel, and restart the receiver, would that work? I want to check if the receiver starts without entering in protection, with that pair removed.
nice work sir, gotta learn a lot from you
Mark, what procedure did you use to measure the Zener with your multimeter?
hi I have rxv465 Yamaha and Its hdmi out audio is ok but in video it seems yellow
how to fix it please somebody give me idea
Thanks! Yes, HDMI indicator did light up when it got the signal (when i used the selector). So that is good to know. Any idea how much say IC1 should cost, or in general, to repair something like that? (Not that I want to replace it myself - a cap or a resistor, I can handle. Not a chip).
Ok, thank you for your valuable input.
Are you bleeding down the B+ and B- lines with that resistor? Also, what value of resistor do you use?
Thanks,
Ben Huebner
I have a Harman Kardon AVR 354 receiver I repaired (replaced L7915) that worked very nice. I didn’t use it for a few months, and then when I plugged it in and turned on, acted strangely. The unit’s front panel lighted up completely (all characters were on). After reset, it functioned “normal” but with repeated (every minute or so) sound dropouts (short, 1s or so). Strangely, during the sound dropouts the front panel blacks out, as if the unit loses power (the power on led is on though), but then comes back and functions well for a little while. In the end (~10 minutes) the sound drops off completely (but the unit stays on, and the front panel working OK), or turns into a whistle. This happens in all sound modes, all inputs, with or without any external connections (even with no speakers - reacts the same, you can tell that from the front panel blackout). Between the sound/display dropouts it functions completely “normal”. I tried repeated resets, doesn’t change anything. The F110, F111 fuses and wire (jumper) from HDMI board to Regulator board upgrades have been addressed by the previous owner. I didn’t see anything similar on Internet, have you encountered this issue before?
Wow. I need to know a lot more. What model Kenwood? Are you a technical type person? Are you able to take voltage readings, etc?
I have a Yamaha htr 5440 receiver and no channels were blown blown channels are usually caused by wiring your speakers at too low of an impedance like if the impedance is lower than what the receiver is able to handle
Are you using the Huntron to test semiconductor's?
Hi Mark,
Yamaha RX-V795a. Shuts off after 0.5 sec. Diagnostic mode quickly (0.5s) shows: "PS PRT 39%". Output transistors (C3856 / A1492 pairs) look OK in circuit. The Noble resistors look OK. The regulator 7812 (x2), 7912 and 7805 (all on the main heatsink) have the proper voltage. Mind you, I only have 0.5 sec to do the measurements. Is there any way to increase this time? I can’t measure the DC offset, too short a time.
the unit work perfectly, if i wait some seconds between power on/standby operaton. if this is a normal operation, i'll go close the cover of the unit. Thanks for your help, and before i forget, nice videos (but a little dangerous for curious people) you posted.
Sorry about any errors in text. see ya.
Is it possible to run a 6.3 volt sin wave into the component via a frequency generator, then measure the component via ocsilloscope in XY mode?
STK IC motherboard problem to5.1 chinl to problem 2 spikes chalu and 3bnd hiy what problem plz
i have a kenwood that was turning its self on and off but would still work now it wont come on the main relay clicks rapidly and has blue flash in it you think it could be the transistors?
Nice repair man!
Great video posts, Mark. I have an RX-V667 that is tripping circuit protection on DC after a lightening strike. All values in the diagnostic menu are normal except for P1-1 (DC_PRT on IC902) showing value 0 instead of normal 32 to 74. Is there a place to start before looking at each amp channel?
***** Start the receiver in protection cancel mode and see if there is a DC offset on one or more channels. DC on one channels obviously means that channels needs repair. More than one is a power supply problem of some sort, or there could be a problem involving Q1072 (not) providing a -12.6 volt bias to all amp channels.
hi i had a question how would i fix my ir sensor on my harman kardon avr 40 i bought a new remote for it but the receiver isnt working with the remote and the remote works good.
Have the same receiver - and I think a lightning surge took out my HDMI circuits. It turns on, but seems like no signal is coming out of either channel. Do you know what it would take to fix this?
Thanks mdzacharias i open my receiver and fixed a broke fan and change two fuse thant blown going to try your advice two questions though when i unplug the hdmi board the receiver does not shut off clicks on and then off over and over but the power does not blow is it possible its bad caps on hdmi boards like the other onkyo's. One more question i have seen your reviews of the multimeters can you recommend a good starter meter on the cheaper side that can handle voltages of a audio receiver
Update2. I tracked the high voltage, back to transistor Q708 (NPN, C2240). I replaced it, and now the readings at the Q716C (NPN power transistor RL) are much closer to the schematics: the transistor base reading changed from 6.2 V to 0.47 (0.4 on schematics). Unfortunately the symptoms are identical, and the display still shows the same PS PRT 39%. Other voltages are OK, no DC offset… I wonder if I can reset the unit, but how, since the display is gone in 0.5 sec. I guess I am stuck.
@costellom5 You mean the desoldering braid? Pretty common in my work. I also was using a spring loaded solder removal pump, if I recall. I don't use that so much these days - too easy to mess up the solder pads.
seems to be a pretty good amp.copper screws for the transistors.
what is that you use with your soldering gun?not the thing that solders,the other one
I found the can that blew off the cap down in the receiver and it reads 16v4uf. They didn't have that at radio shack. Will a more common one do? The cap was in that assembly that screws to the heat sink above the stuff you are working on and has two 5 or 6 lead cables coming off it. Also wondering what soldering iron and vac you are using. Thanks, Scott
Scott Young You can solder in a 4.7uF at 16 or 25 volts. Cut the leads fairly short and first solder the original circuit board pads a little, then tin the capacitor leads with solder. You should be able to use the soldering iron to then solder the leads to the board. Be sure to observe polarity of the cap. The old solder station was a junk MCM model and it died. I went back to using my old Weller station. The other device you may have seen is a Denon Instruments desoldering tool. I don't use it much anymore; a friend gave me a hot-air gun with a pinpoint nozzle attachment. Don't know the brand.
goodmorning, mark, i have a yamaha rxv 661 and sometime ago i was playing a CD i had just gotten whilst i was in the yard. unknown to me the CD was recorded high and so when i heard the volume came up i ran to lower it but was too l8t. the reciever just shut down n i waited a few minutes then turned back on i saw the display but shortly after the power just went back off i tried it again this time all i heard was TWO CLICKS. what do u think is my problem and can it be fixed?
I think you need to look at the PRV line on the Main (2) board. It's the board along the top of the heat sink, so you should be able to get to stuff pretty easy. The PRV line sums all the power supply lines and provides an error voltage for the microprocessor. This winds up over at IC21 pin 35. Occasionally the backup capacitor C103 might leak and give false trigger on the micro but usually just a bad regulator over on Main (2).
Hello mark i have a rx v373 with Dc prt 255 hi error can you please guide me where to start checking for faulty components.
I know this video has been uploaded from 8 years but hope you still can help me thank you in advance
i have a yamaha rx v1900 av receiver,both right and left channels were shorted out destroying four power transistors,four driver transistors,two 5.1v zener diodes,two 220 ohms resistors,also one of the power supplies were damaged that supply the main amp board with a dual plus and minus 61 volts,this has been repaired but the main amp board is dragging the dual supply down very low,i cannot find any more shorts on the main amp board that may be causing this problem,can you please advise me.
Ok, I can't quit. So I checked the noble resistor and it is bad. I going to replace those two transistors also 'cause they are so cheap and apparently go bad. But can you say how to mimic that noble dual emitter with p/n mcm 28-0520 (since that part not available)?
Scott Young You might want to double check that resistor - they rarely go bad on the Yamaha's. If the outputs are bad I guarantee the drivers are bad, and probably the 5.1volt zener diode as well. Also the 100 ohm resistor that sits between the emitters of the drivers should be checked. I haven't seen dual .22 ohm 5 watt resistors on eBay. If it's really bad, usually only 1/2 is bad and the other half could be bypassed with a single. If you're in the U.S. B&D Enterprises would have the dual, I'm sure. I have a drawer full of the things at work. They're really common if you work on these things. Many of those I have are pulled from scrappers.
Hi mdzacharias, I have got RX-V630 which turns on for a brief moment and shuts down. Sometimes there is message check SP wire on start. I have disconnected all my speakers but still the problem remains. Can you guide me on where the problem would be or have you got a circuit diagram for it?
Thnx mark for the reply.
The technician guy had connected A TERMINAL rights posts to the right spkrs and left to the left speakers, same way he had done with the FRONT B and assigned as extra presence.
I tried the B TERMINALS right & left to one speaker and done with the other spkr too. It sounds grt. But the front A TERMINALS doesn't give any sound output whn connected the same way.
A and B should sound the same since they run from the same internal amplifiers. Surround, Center, etc are different internal amps.
@@mdzacharias something's s miss. Have called the technician. Let's c, will update once done.
Hi Mark, I have a Yamaha RXV 661 Receiver and the Polk Rtia 3 connected to it via the front A and front B/ zone 2 with extra SP assign mode.
It only plays the LEFT SPKRS woofer & RIGHT SPKRS tweeter. Can u pls throw light on the issue as I am not able to know work it out.
Sounds like the speakers are the problem.
@sidsasi The most likely thing at this point is a blown amp channel. Are you a technician?
Update. Using the trick you mentioned before, I was able to take some measurements. I also used the light bulb as a precaution. It lights up a bit when connected to the power outlet for a second, and them dims out, so no over current issues, as predicted. The rear L power transistor Q716C (NPN) has 6.32 V at the base (should have been 0.4), 0 at source (OK) and 38.5 (40 on schematics) at collector...continued
@ mark zacharias .Do you repair these receivers for the public. I have a Yamaha RX-v665 that I believe may have been damaged from a lightning surge. Having trouble trying to find someone near me who can repair it.
I'm not really wanting to deal with shipping and receiving and all that; and besides, lightning can be pretty devastating, often unrepairable. What is the receiver doing wrong? And are you sure it was lightning?
Do you mean no sound, or no HDMI video?
Thank you for your reply mark.I checked the mute drive circuit and one diode D12 reads 14v on both sides so i de soldered it on one side and the eq works fine now.maby a faulty cap or transistor.I'll keep checking.
Hey mark love thank you for this video I have the exact issue with my v661 I have done changed the output transistors but am struggling with the other repairs like the driver transistor I need assistance with the range it should read when tested normally and furthermore. I would like to if possible repair as I would hate to see it end as land fill. Any help would be grateful.
+Andrew Shorter If the outputs were bad ASSUME the drivers are bad, also the 5.1 volt zener diode. Also check the resistor between the emitters of the driver transistors. After these parts replaced, check resistance from base to base of the output transistors and compare to other channels(s).
Hi, i have an amplifier which hv the label on the motherboard for the capacitor to be 2200uF 35V. However, the manufacture put 1000uF 35V caps in it. can i replace it wh the 2200uF 35V caps instead according to the board?
Normally this would work fine but I would not necessarily expect any improvement unless one or both of the existing capacitors were defective.
Hey Mark, My RX-V661 turns on and has a display for about a second then shuts itself right off. Any help? It does not go into protection mode, I also checked the channels and they all appear to be good. So I'm at a loss?
You need to check the output of all the fixed voltage regulators on the Main (2) board mounted higher up on the main heat sink. Also the outputs of Q1045 and Q1046 (plus and minus 59 volts approx) and Q1000 (about -12.6 volts) . In order to facilitate troubleshooting problems not involving a blown channel or hard shorts, there is a protection cancel feature in the diagnostic menu. While pressing and holding "straight" and "audio select" press the Master power button and continue to press the first two until the SLEEP indicator flashes on the display. You can then troubleshoot the DC voltage problems at your leisure. If you have any technical skills and a decent multimeter anyway...
...
Hi Mark. I have been looking though your videos seeing if you have encountered my problem. I have a Yamaha RX-V667 receiver. It was working fine until recently it started constantly switching DSP modes. Its happening intermittently. I some of the other buttons on the front are also activating. Is it possible just to replace the front panel? Where could the replacement part be ordered?
pvdeluca Kind of unusual problem. The front panel switches are part of a couple of resistive networks. Any leakage could trigger this. Like if some liquid got in there somehow, maybe causing some corrosion. Tact switches can also be leaky but this is less likely. The part number for the front board is WU427500 for the U.S. model only. Ending in 600 or 700 for other markets. Probably fairly expensive.
Mark Zacharias Hey thanks for the response. Ive googed for days to find someone with the same problem. My apartment is very humid so this might have caused the issue. Too bad it was a great amp. It would feel like such a waste if i didn't get this repaired.
Hi Mark, Am bothering you again. Is it possible to arrange a WJ697500 from USA. Will it be compatible with the RXV 661 ( L model).
Thanks going to try to check those things hopefully but the receiver stays on when i turn it up but past 44 - 45 the sound cuts off not the receiver but im guessing its the same problem
Is there anyway you would know how to fix a Harman kardon that get power to the ac outlets but nothing else work
+Brian Wallace I would need to know a whole lot more. I'm guessing you may be out of your league here. A person with any technical ability would have already given me the relevant information.
discupa la molestia amigo yo tengo una yamaha RX-V650 que prende y se apaga nomas se oye k entra el relay y se apaga de casualidad no me podria orientar cual sera la falla si me puede ayudar selo agradesere de todo corazon saludos desde villa juarez navolato sinaloa mexico
tomas arteaga barreras no habla.
In the diagnosis mode of Yamaha htr 6030 a message for a very short time
"PVR PRT 59"is displayed and the receiver shuts down.
What does it mean and where does the fault lie? It definitely means power supply issue but what does the number 59 signify ?
Indicates a power supply problem. There is a Protection Cancel mode that will allow you to keep the unit ON while you troubleshoot. email me at mark_zacharias@sbcglobal.net and I can email you the service manual. Most likely a bad voltage regulator IC like a 7812, 7912, etc.
Thanks a lot Mark.
My email is balrajacharya@gmail.com
i have a yamaha rx-v367 that when i push the power button it clicks like its coming on then clicks off. please help me figure out what it could be id love to send her to you shes been my reciever for over 10 years and this is the first problem ive had from it.
+shaneglover99 The most likely thing is a bad amp channel. Might not be cost-effective once shipping etc is factored in...
Mark, I have a Yamaha RX-V2090 that I bought new (for $1549!) somewhere around 1996. It has been a great unit, but over the years has lost some of the channels for the speaker outputs. I have downloaded the service manual, I opened up the case tonight, and am looking for obvious signs, like discolored boards, but am not quite sure where to begin testing. Any advice on where to start? Thank you!
I think I would get the receiver into diagnostic mode and reset to defaults. Good place to start anyway. Under "Preset Inh" switch to "Preset RSRV"
Mark Zacharias Thanks for the reply. I have figured out how to get it in diagnostic mode, but it seems some of my buttons are sticking. For example, if I push "Tape 1", the "Tape 2 Monitor" comes up.
It seems a few of the buttons are mixed up with the one next to it. I do have the remote, but has the same issues. I'm not too surprised for an 18 year old unit. What can I use to clean them up with?
Can I contact you off of youtube? I may have a lot of questions, if you are willing to help...
Thanks!
I was able to take the remote apart and clean it. It appeared someone (besides me) poured a few cans of Pepsi inside. I just (carefully) used soap and water to clean the contact side and the button 'sheet'. It has never looked so good! Would something like rubbing alcohol also have worked on this, and/or the receiver?
great video
Mark,
I have a RXV-665 that has the STK443-130 amps....The unit had a similar problem,shutdown and I can get the self diagnostic to read - DC PRT :075H
Do you have any experience or tips on this model,,?
Thanks,
Steve
Steve Bavis The receiver can be forced to stay on for troubleshooting. Are you a technician?
Just curious if you've run into the same issue with a rx-v795a Yamaha and if it could possibly be the same fix? Seems like every blog I've read says something different. Relay clicks but no power. Thanks and good work!
+Justin Bergendahl The most common thing is a blown amp channel caused by bad solder connections at the bias transistors. I would check continuity of the main power transformer first. If the unit went out after playing too loud for too long, the transformer could be bad. You need some skills like soldering and know how to use a multimeter or you're probably out of your depth on this one.
+Mark Zacharias well I changed the relay on the main power thinking it was the problem but still getting the issue. Main transformer has 120v. The aux outlets work without power on. It has to be within the amp or a capacitor dried out. You obviously deal with these a lot. Just trying to narrow it down. All help is much appreciated
+Justin Bergendahl You should check continuity or the primary winding of the main power transformer.Should read a very low DC resistance. UNPLUG from the wall first! Next check for emitter-collector shorts on the output transistors. The smaller amp board amp channel nearest the rear of the unit is most common.
Hi Mark,
My Yamaha RXV661 which was running fine for the last 4 years suddently refused to turn on. I was trying to plug and unplug a few devices from the same power plug when I found the 2 of the SCENE button LED turn on for a while. Thereafter, the device simply refuses to turn on. Checked the fuse out of common sense, but they seem ok. What could have gone wrong. Will appreciate your inputs Mark.
I got that last part in fixed that but my sound still cuts out at about 45 or so and was able to stay on for a few seconds at a higher volume i am not sure seems like something with the front cover because it did stay on at almost max volume. But it still says check speaker wire for the first 10 seconds when i first power on the unit after plugging it in to the wall for the first time.
I am bit familiar with electronics. I checked all C4468 and A1695 transistors with DMM, could not find any shorted ones. I have not checked at resistors and diode yet.
So if it blows a cap and quits, is it gonna have a bunch of stuff bad?
Scott Young Caps are very rarely bad in a situation like this. A blown channel can be just a couple output transistors and nothing else - it it can be almost total destruction of the board and a large number of components destroyed, or anywhere in between.
Some people think that "90% of problems are caused by bad caps". This is total bullshit. There were batches of bad caps affecting flat screens and computer motherboards a few years ago. Other cap failures are generally very random, unless they are caused to be bad by other factors - heat, over voltage etc.
Hi Mark, I have a RX V477 working on, its brand new, got off Ebay, in protect mode. Got into the diagnostic mode, first of all I don't understand what all that stuff means in diagnostic mode, so far I pulled and replaced all the output transistors, I had already bought all 10 anyway, but the old ones checked fine as did the emitter resistors, I'm new to electronics, went to school and trying out a few of these bad stereos to get some experience. What I need is a schematic of the power amp section, can't find it for purchase or free. And something about how the fault mode codes work. Apparently I have some other bad items in there I failed to check. BTW in fault mode I seem to have one dead front channel. Good learning experience!! Thanks for the help. Subscribed!!
+Vernon Bosshard This vid cleared up a lot of confusion, so much crap on the net about why units go into protect mode, but from what I read is its always due to DC offset on the power transistors or something to do with the power amp section causing a fault. I bought a few units off Ebay for practice, got a Sony and found the schematic online. What size resistor do you use as a Cap bleed off?
+Vernon Bosshard www.hifiengine.com/manual_library/yamaha/rx-v477.shtml
You have to register but it's free.
+Vernon Bosshard I often use a 750 ohm 20 watt resistor to bleed of the higher voltages, especially if the voltage on a particular unit doesn't bleed off by itself. Lower voltages sometimes I'll use a larger eight ohm resistor because it bleeds off faster.
I have Pioneer VSX921, suddenly notices there is not audio from SBR and SR
channel; I checked that there is audio at relay PIN. Other channels are
working fine. could it be a problem with relay? any logic that is not
turning relay on. Thanks in advance
Looks like there are two separate relays involved here. Maybe try a full reset before going any further.
Thanks a lot Mark. I also had doubt about the relays. I did reset and there was no luck. Then I checked a capacitor leg after relay RLY6 and found audio. Now I can surely say that the problem is with track or the speaker pin solder joint. Accidentally I pushed the speaker socket and it worked! It is a loose fault or dry solder problem. Since opening the whole circuit board I made a jumper about half an inch from capacitor leg speaker tag. It’s now working fine. Thanks again for your reply.
hi . i repaired a yamaha htr-n5060 with a power supply fault. The fault was a 22nf capacitor in the power supply. It still has fault in memory stored. I see it in the diag menu . I goto menu 9 facotry reset but i don't know how to clear the fault (factory reset) . what button on receiver do i press to confirm factory reset? when turning on receiver it is shutting down because stored fault? Or is there still a fault somewhere? thanks
On a Yamaha, each menu selection in the service menu has the main selection and a sub-menu selected by one or two other buttons. In the reset portion of the menu, you must select the reset, then just turn the unit off. The reset will be effective at next power-up.
• Operation procedure of DIAG menu and
SUB-MENU
There are 23 MENU items, each of which has some SUBMENU
items.
DIAG menu selection
Main unit: Select the menu using the PROGRAM knob (RXN600/
RX-N600D/DSP-N600 models) or (Forward) and
(Reverse) keys of PROGRAM (HTR-N5060 model).
SUB-MENU selection
Main unit: Select the sub-menu using (Forward) and
(Reverse) keys of PRESET/TUNING.
@@mdzacharias thanks . when i reset. it is still going into protection. when i goto menu nr. 20 there is p1prt 032 stored. in the service manual i read. i understand thay value 17 to 66 is normal. so 032 is normal?
PS1/PS2 (Power supply voltage protection detection)
Power supply voltage protection value (Normal value: PS1:
17 to 66, PS2: 36 to 53)
PS1: Detects +5S and +5DAB
does this mean there is still a problem in the power supply or in +5S and +5DAB ? this are voltage regulators? thanks.
ive not bolted back the main amp board to the heatsink and ive disconnected the thick power wires from the collectors of the power transistors cause ive already had 4 more power and driver transistors go short on me cause of a fault with the plus and minus 61 volt driver supplies,there seems to be something on the main amp board causing the dual supply to be very low,im having to run the amp in diagnostic mode so i can test but i dont know what else to do and yamaha uk are very unhelpful.
Wierd i was able to get audio when turning it on just now but when i pluged in the fm antenna it shut back off. There is a fan inside that is not working does that cause the receiver to power off like that its 120mm fan was going to replace it
Hi i have a Yamaha RX V667 and only had about 1 year from someone who never used it now the Power Transformer was all new looking silver on top through the vent but just noticed that there is browning on the top which looks like har syrup sitting on the top. Is that due to the heat over the time that has turned the coating Brown ??
Mark Chancellor I've seen stuff like this from new. Looks like a resin coating. Otherwise someone might have spilled something. If the receiver works I don't think I'd worry about it.
Mark Zacharias
Mark Zacharias
Hi thanks for the advice it must be a resin if someon spilled something then the heat generated will cause a burning smell. Cheers keep up the good work
Hey Mark,
that is a great and very useful video!
I have a Yamaha RX-V550 reciver, and it works perfectly, but sometimes it shuts down with loud boom when I switch between output programs (2CH, 6CH, Dolby Digital, etc.). The other problem is: when I plug in a headphone jack it works well only in 2CH mode. In other mode I hear only distotred music. When I pull out the headphone jack in 6CH mode, the receiver shuts down immediately. I checked the protection codes in the Diag Menu, I found only this: DC PRT 14 C
Can you help me, what can I do with this reciver?
Thanks!
Peter
This type of thing could be caused by a bad muting transistor, if only on one channel, or a loss or a DC bias voltage like "-12 AMP" from Q253 on the main board. You can power up the receiver in"protection cancel mode, described on page 23, but if the problem is intermittent you might be waiting a while to get any results.
Thank you! I will check the muting transistors and the bias voltages.
I would definitely be looking at the power supplies, like plus and minus 15 volt (maybe + or - 12 volt) lines, also any muting circuit that may be used.
@RSethTV No, it's homemade. A small 6.3 transformer and a few resistors in a project box, hooked up to a BK scope in X-Y mode.
So I have this same receiver, rx-v661 which works fine, however the display no longer works. Tech seemed to think it was a problem with the power supply. Any ideas on that? If so do you know where I could get the parts to replace and fix it? Great video by the way
Nice work, I have a yamaha rx-v667 and it works great but i have trouble getting radio stations to come in. after looking it over i see the antenna plug is bent up kind of funny and I'm thinking this might be a bad connection. would this be easy to fix?
Should I take it to a shop? I have done some soldering before but wanted to ask. thank you.
dankbobby The tuner is a complete module and fairly easy top replace except it is situated kind of underneath the HDMI board. The part number is WQ756600. List price is about 40.00
Mark Zacharias
Thank you very much.
Yeah your right about that,I went to turn on the amp and i heard a loud snap and flash..I thought the transformer went,but it was the circuit lifting up from the board soldered it tested it same thing so i put a jumper on it.the yamaha RX-V2500's fan circuit is still not working so i improvised it with it's own power supply Until i can order a new board.I know yes i am an amateur,but thank you for your informative video's.
If the bias transistor is bad I would recommend ordering the Yamaha part number, VK432900. You might be able to get away with a 2SC2603, but the problem is the bias would probably be somewhat at variance with the other channels, and there is no real adjustment provided.
Hi Mark. I have a Yamaha RX V659 that immediately goes into protection mode. The error code is dc prt 026 hi. There is no short found on the output transistors. Any suggestions? Thank you.
This is because your problem is NOT the output transistors. The "PS" indicates a power supply fault.
Mark Zacharias Thank you for the quick reply. The error message did not include “PS”. Does “DC PRT” indicate a power supply fault?
@@IIWII9 DC PRT indicates a DC offset on one or more amplifier channels. If the problem is on one channel only the likely culprits are the differential transistor pair or the low frequency roll-off capacitor for that channel. You can email me at mark_zacharias@sbcglobal.net
Hi Mark, I have a RX-V771 and it goes to protection mode few seconds after power i powered it up. No standby power light when its off also. When i do the self diagnostics, it shows PS2 PRT: 186H. As per manual, this error is caused by abnormal voltage reading in -VP, +5A, +5T and 3.3s but this voltages are present and normal as per my checking. The other vital voltages on the AVR are present too. any idea what is wrong here? Thanks in advance
To start with I would check the output of the plus and minus 12V supplies - I suspect the 7912 negative regulator. They are on the main board.
hi +Mark Zacharias, unfortunately all the voltages, (+12, -12, +18, +5, amp dc power and other relevant voltages) are ok. any other hint? any option to trick/cheat/bypass this error ? thanks
power amp channel are all ok too.
Well something is triggering it. The PS PRT line is comprised of summing resistors wich go to each of the monitored voltage lines. The center point where they tie together is the PS PRT line. Occasionally a resistor is bad, but more often you just have to find the high, low or missing voltage source. There's no trick to make it work in spite of the protection problem, except the protection cancel part of the diagnostic menu, which only works so long as it's in diagnostic mode.
Nice video! I have one of these that just came in our store and the owner said they were listening to it LOUD and it went off and now when you hit the power button there is nothing. Any ideas? Think it is fixable?
UPDATE: I can hear a click on then off.
Ken Shipley Need to check the primary of the power transformer.
Hi mark, Im looking for some help if could please. I got a Yamaha RX-V367 which shuts down when I raise the volume, for recommendation of the troubleshooting book I change the cables and the problem still happening, also I check every single speaker separately and the receiver still shuts down. Can you tell me what can I do or what sort of circuit can I change from the internal panel. Thank you so much for your time.
Wilson Bastidas There's at least a couple things that could cause this. Perhaps a bad output IC, for example. A severely clipped waveform is interpreted by the microprocessor as a DC offset. A DC drift arriving at the input of one of the output IC's could case this, but it's unlikely. Bad solder connections at an output IC could cause this also. You should disconnect all speaker wires from the back of the receiver and see if it still shuts down with increased volume. That would be useful information.
Hi Mark, Happy new year 2015, txn for your answer, well I disconnect al speakers and the receiver doesn't shut down which mean the problem can be made from the speakers. do am I alright?
Do carefully check the speaker wires. It's important that no strands cross over and touch from positive to negative.
hi mark will you please let me know how my hdmi problem fix RX-V465 video is yellow and all wires is good I checked so what might the problem should I check the regulator volt and capacitor please suggestion me
abhisek bhandari Normally in this situation the HDMI (Digital) board need to be replaced. Too expensive. If you are very good at working with surface-mounted IC's you could try replacing IC7 on that board. It is an SIL9134CTU 100-pin surface-mount IC.
my yamaha rx v730 is identical simptoms. just one clik and wont turn on...
hi mark, one question...
I have a Yamaha HTR 6130 with the following error: THM PRT 207, 186, 170.... and can´t reset.
No, it would not reset. There is a temperature sensing IC on the regulated power supply board. Possibly defective or maybe bad solder in the general area. IC238.
Jeff Allan I have been trying to reply and CZcams won't post my response. Try checking the voltage regulators on the large heatsink.
thanks! it was a bad solder in this area. Again, thank you very much.
Hi Mark i have a rx-v3900 it powers on but no sound from any channel the AM FM radio or anything input to it and speakers are good use them on other 3900. any ideas thanks
The 3800 and 3900 are probably two of the most difficult models for service - that Yamaha has ever built. Even an experienced technician would have his hands full with this one. Here is a link to the service manual. Good luck.
elektrotanya.com/?q=showresult&what=Yamaha%20rx-v3900&kategoria=&kat2=schematics
If the multi-channel direct input works, maybe a problem in the dsp area. If not that, maybe check an electronic volume control IC.
thank you ill have a look at it when i go back home im working in North Dakota now im in nw MO
The trick on these is to prepare a double ended POLARIZED AC cord; Take the receiver's own cord and plug it into one of it's own switched outlets. Take the double ended cord and run it from the the other switched outlet to the AC outlet or variac. The receiver will shut back down but the internal voltages will stay up. Make sure that the AC cords maintain the Neutral and Hot relationship, or BIG SPARKS will occur.
Hi wanna know if you provide repairs for the public i have a dead harman kardon 3700 with no power no stand by light
@killerkoop33 I cannot find this model number listed. Not a U.S. model anyway. This could take some real troubleshooting. Are you a technician? The likelihood is either a bad main power transformer or a high-current shutdown, such as might be caused by a blown amp channel.
Hi Mark,
My knowledge of electronics is very basic.
I have a Yamaha RX-V773. Failed while watching TV - while at normal volume...
The red power LED glows dim, no other display visible. Press the on/off button on the remote, the red led flashes dim.
The fuse "was" OK, until I tried to do the factory reset to default. As soon as I pressed the button combination on the front panel to attempt the factory reset, there was a big flash as the fuse "went open circuit".
With the fuse open circuit and using a couple of different control panel button combinations, the front panel does light up with text and numbers... This proves the front panel still works - but I think that's it - probably nothing useful in the display
I do not know if a test I performed proves anything, but connecting my multi meter (set to ohms) across the speaker output connections gives a resistance reading on all channels EXCEPT centre, left surround and right surround. So, that is 3 speaker connections adjacent each other that look bad to me (unless this test is useless of course).
Some history - which may have been the beginning of the failure, some months ago, the centre channel started to cut-in and out... I thought the amp was history so I went out and bought a Denon. While performing the unit change over, I found that one of the centre channel speaker wires had come out of the connector =:-( .... Anyway, the Yamaha still worked after re-connection the speaker wire, so I installed it at my holiday house where it worked fine for some weeks, until it failed a few weeks ago while watching TV....
Sorry, not much info, but on this brief description, what is your feeling - trash it or do you think it is worth fixing. Is my output test valid?
Thanks Mark,
Jim (in AUS)
If it blows the main fuse something is seriously shorted. Yamaha's protection circuits work so fast in the event of a current overload, they usually cut off before a fuse can even blow. Anyway, forget about checking resistance at the speaker terminals for now. Check resistance emitter to collector of the output transistors, focusing first on the channel you were having problems with.
If there's no particular issues found there, check for a short from the collector of any NPN output transistor to chassis ground; do the same for any one of the PNP outputs. (each channel's NPN collectors are tied together inside, so are the PNP's) Occasionally there is a bad mica insulator. If this is the case the can also be a carbon path formed from that screw hole in the heat sink, right up through the body of the transistor. In this case the transistor must be replaced along with the mica. Merely trying to clean away the carbon as a fix will not hold - I been stung on that one before.
I had another Yamaha a couple days ago with a similar symptom. One of the main filter capacitors was shorted . Fuse blown - measured dead short from the collectors of (PNP or NPN - I forget which) output transistors to ground.
G'day Mark, thanks for the update. Just wondering if you might be able to point me in the right direction to download a wiring diagram for my RX-V773.... Been searching but not having much luck.
Thanks,
Jim
jim.stapenell@gmail. com
You can email me direct at mark_zacharias@labolgcbs.net and reverse"labolgcbs" to read "sbcglobal". I can send the manual in RAR chunks.
G'day Mark,
I did reply to your email address - did you receive my message?..... As it happens, I found a manual online for an RX-V673 which I think is similar to my RX-V773... Anyway, I wonder if you might be able to comment on something I found. My relay does NOT click when the power button is pressed. I unscrewed the board with the relay - fitted clip leads between the ground points on the board and the unit metal frame. I then switched on the power, applied multi meter to measure the voltage between the closely grouped 5v and ground (?) at the 11 pin plug connector - I measured the voltage OK, but when the multi meter leads contacted the 5v & Ground points, the relay clicked.
From this info, can you possibly identify any obvious faulty components - or at least group of parts I could replace as a test.
I know this request is a long shot but thought I would ask anyway. The reason the relay clicked when I connected the multi meter is probably because I had the board disconnected from the 11 pin plug? Who knows....
Let me know if you did get my email...
Thanks Mark,
Jim
What Driver Transistors did you use to replace the c4614 and a1770 transistors?
2SC4027 and 2SA1552 are the replacements I used.
2SC4793 2SA1837 are used by Yamaha in some step-up models. They survive more often if the main output transistors fail.
Thank you so much, busy rebuilding the front right channel and could not find any equivalent parts that match.
Watch out for that 5.1 zener...
will check and replace if necessary, thanks for the quick feedback awaiting the parts from ebay now
No, it doesn't. I also visited the local yamaha service center and they said that the DSP PCB has got rusted for whatever reasons. Also gave the faulty PCB part no WJ698200 which needs to be replaced. Now, this PCB is not available in India. Can you suggest where should I get this from.
Hi Mark,
Thanks for the clip!
Do you have any experience with a RX-V363 receiver which turn off after a short while? Sometimes it will take several seconds to turn off, sometimes a couple of minutes - but it will never keep on working.
Thanks!
sblueeye After it has malfunctioned, let's try a diagnostic mode. It will be important to read the display during the first couple seconds. It will read DC PRT followed by a number, or PS PRT, etc.Start the diagnostic mode by pressing and holding "straight" and "audio select" then pressing the standby/on button. The receiver may or may not stay on. Get that initial message and report back to me. If it's a PS PRT message should be relatively easy power supply type problem. DC PRT could be more trouble.
Mark Zacharias I get a PRV PRT 154 message (I disabled protection)
sblueeye Best guess - a bad 7912 voltage regulator IC. Possibly IC 237 on operation (2) pcb. Try to find that -12v line - see if it's missing or way low.
Mark Zacharias Can I tell by checking the -12v if it's the 7912 or one of the 7805? Also, I assume I need to do all that when protection is off, is that correct? Thanks so much for helping!
sblueeye You should be able to check the output of any of the regulators - or anything else you can reach in there - with the unit in Protection Cancel mode. Don't forget - I accept Paypal!
Question, I have a yamaha RX-V373 that just 2 days ago went dead while I was watching it. It will not power on at all. In your opinion is it worth fixing or would I be better off buying a new receiver?
Impossible to say for sure until the troubleshooting is done. The most common problem I have seen with these is a bad amplifier output module. There are two in this model, one is a two-channel version and the other is a three-channel version - hence the five-channel receiver. More often the 3-ch IC goes bad. The protection circuit has the receiver locked to avoid further damage.
Mark Zacharias Hey Mark,
I also have a 373 that won't power up. The relay trips when I do the tone control, straight, and power reset. It's a few months out of warranty. No signs of heat damage and fuse is intact. Any ideas where the most likely cause is? No symptoms prior to shutting off. Working one day. Not the next.
Sounds like the prior one - a bad output IC.
Mark, great video! I have a BA in EE but haven't really used anything I learned since I got my new job. I have a Yamaha Rx-v765 that I believe is in high current shut down mode like the one in this video. When I plug it in I hear 3 clicks from the 3 relays but there is no display. I have checked voltage going to the display and it measures close to what the service manual says it should have.
Do you happen to have any tips or tricks to verify it is in high current shut down mode or any other tips on where to begin troubleshooting?
Part of me says I should just send it in for repair but my inner nerd is telling me I should be able to fix it myself.
These can have a variety of problems. If the main power supply voltages to the output transistors is staying on, then probably not a high current shutdown. Maybe the display circuit - maybe a blown channel. I would start by looking for any shorted output transistors. I can probably send you a pdf of the service manual.
Mark Zacharias I have the service manual but everything I have checked so far seems to be correct. I haven't dug to deep into yet though. I basically just checked a few things I could easily get to like transformer and display board voltage.
I was only using the rear speaker outputs at the time it went out as my main speakers are powered.
I should also note there is about 56 volts going to the chassis.
I will check the output transistors next. I appreciate the reply.
Mark Zacharias
None of the output transistors appear to be shorted as far as I can tell. They all have high resistance across collector and emitter. I'm not saying my in circuit transistor testing is 100% percent accurate either though. I may do some more exploring in the display circuit.
Mark, I think I may have found an issue. There is a 25 pin ribbon cable that goes from the main video board to the display circuit. When analyzing the voltages coming out of the video board to the ribbon cable there are several discrepancies. Pin 24 which is labeled 3.3DSP is supposed to be 3.4 but I am reading only 1v. Is that just because of another problem and the microprocessor is telling the display not to turn on or could the processor itself be damaged.
I think I maybe getting in over my head here but it is certainly fun. Sorry for hijacking your video.
Jeremy Meyer
I have seen things like this cause a "no display" problem. In my case. I replace the digital board, where the 3.3D (for display) is generated. (Seen this twice only)
@killerkoop33 The power transformer usually only goes out if you've been running it really hard for a couple hours.The transformer can be checked by a knowledgeable person. Also Yamaha with a blown channel may pull so much current at turn-on that the protect is triggered instantly, you never even see the display come on. If the transformer is OK this is probably the case. I wouldn't recommend just ordering the transformer til you know it's bad. About 135.00+frt. US model.