What an interesting statement. The manufacturers don't want these repaired. We are facing an environment crisis, that we may not recover from, and these companies promote waste. This has to change and very soon. I appreciate more than ever the quality electronics from the 1970's and 1980's. A person such as yourself could fix almost any electronics from this era. God bless.
Agree there are speakers tube amps turntables from way back when that out last morden day equipment. FACT another thing is how you use and look after it can play a major part also. Im lucky my home cinema i put together in 2012 is all in perfect working order. And was not cheap £8000+ made me give it that loving touch 😂😂😂
Sadly, you're correct and this is the case on almost every product. Even basic ones. I bought a manual can opener that cracked the very first can I tried to open.
It's true but hdmi arc is convenient to have, and room correction etc. It's sound united setting the trend for expensive electronics to be junk in reliability just to save a buck.
I tried explaining this fact about the environment to David Pogue and Scientific American, unfortunately, they are too tied up in their politics to examine reality.
Hi Dave, I just want to thank you for all that you do on your channel. By following along with your troubleshooting procedures I was able to fix my Yamaha A-S500 amplifier yesterday with an intermittent output on the right channel. I tracked it down to one of the protection relays and after re-flowing the solder connections it now sounds as good as when it was new. Keep the repair videos coming! :)
I have a Denon 1908 that had gone into fault and the client just told a colleague to take it away! The coaxial feed from a Skybox at the head end wouldn't work via a converter. Skyboxes used to only have full surround from their digital outs. Long story short - it finally landed in my lap after everyone else had given up (It was an AV installer company with no repair engineer). It just needed a factory reset!! I still have it as my home cinema set up. I had an issue a few years back in which it literally Screeched at a high level, moving the input leads cleared it. When I had lot's of time I decided to re-solder them, but they were fine! But then I saw that a Single strand of speaker wire was touching the main body, I changed to Banana plugs and it's been great ever since! These designers go to the pub each night and come up with more creative ways to make equipment non serviceable. And have a good laugh, no doubt. Unfortunately - the last laugh is Ours! Well done!!
Got my AVR-589 fixed, thank you! It was the -15v (7915 regulator) on that little power supply. Intermittent for the last few years and it finally fully failed a couple days ago.
I really enjoy and have learned a lot from your vids Dave. I have an 1803 on the bench right now...easy diagnosis as the previous owner shorted the center channel and blew the output transistors...The darlington is being replaced too because it is out of tolerance, but couldn't find the OEM, so I had to research for an equal...pain in the butt! At least taking the boards out gave me an excuse to completely clean the unit.
Well done. The PDFs of most service manuals for Denon (Pioneer, Onkyo, etc) A/V units are readily available on the internet. These units usually offer a diagnostic mode that will display a message or give a code for the type of fault shutdown (DC voltage, short circuit over current, etc). By studying the schematic, you can narrow down to the faulty block or component. The various power feeds can be disconnected which can help isolate the problem down to a specific board, e.g. remove power from main amp board and unit powers up OK means the fault is on the main amp board. There may be safety interlocks between boards - so this method may not always work.
wow now that denon probably had enough screws to put up drywall in two rooms you get the very pateient person award . the last time I saw something with this many screws was a huge masterwork reciever with quadrophonic and there were over 55 screws holding everything in place good job as always nothing bad ever stands a chance to win with you on the job bravo
great job as always each video is a new adventure with great gear and the end result is always the same you make the gear like new thank you for sharing this
I have actually seen this same stuff and I am pretty sure it was solder resin used during assembly... it is almost the same as that circuit glue you have talked about ... over the years it becomes conductive... thus triggering the protect circuit ... I have a neighbor that had one for approximately 15 years and it was triggering the protect circuit... cleaned the entire board with isopropyl alcohol removing the solder resin used during the manufacturing process... and just to make sure re-flowed the output transistors... no more circuit protection kicking in ... I suppose after washings during production the solder rinsing fluid becomes too saturated with resin to fully clean the resin and over time it becomes conductive enough to trigger the protection circuit in all honesty I believe that was the problem and that's the crud you saw ... I am not certain but I think the power transistors are solder by hand and they don't clean the resin afterwards... and over the years it becomes conductive enough to trigger the protection circuit to activate... my neighbor's unit functions perfectly... during the cleaning the resin was very brown as it was absorbed by the old towel if I understand correctly the resin is a very mild for acid to clean the surfaces as they are soldered in place and that explains why it becomes slightly conductive as time passes... I recently had the same trouble with my computer board ... it wouldn't even POST (power on self test) prior to that I had a hard drive (4 total) that Windows kept popping up messages cache couldn't be read data maybe lost ... and it would disconnect from the drive completely.... after I did the same method cleaning the entire motherboard it has not given any messages about not being able to read cache from or to the drive and it posts EVERY TIME NOW as well ... I am very convinced that the traces of solder resin will cause problems over time... most devices these days use EXTREMELY small current signals that can be wiped out or at least be undetectable not to mention how the tiniest currents these signals push through to other chips and circuits anyway hope this helps someone that can't find any bad components yet the device still won't work correctly
Thank you for this repair footage, I have the same problem on my Denon AVR2307 AV receiver, hopefully, I can fix this too as your suggestions. 2 fusible resistor 0.22 Ohm and 15V regulator LM 7815. Two thumbs up!
Wow. that much disassembly looks like a nightmare. I have a Denon that one channel is not working. I think it is probably cheaper to buy a new unit. This one is 6 years old. I have to assume that the cost of all that work would be more than half of what a new unit would cost, (assuming about $500 is my budget.) Great work and patients. You are a master electronic technician.
I have a Goldstar brand amp that I assume is from the mid-80s. I picked it up because I liked the looks and it was just a buck. It has a 1.5 amp fuse inside that looks like it got a little too tired one day. No smoked glass though. It also has a whopping 15 amp fuse that I popped when I flip the voltage switch to 240. The power transformer made an interesting hum before the fuse went
Dave, i feel really sorry for you as i repaired the same unit back in 2015 and i hated the design :-( On mine, one channel had blown up taking nearly every part connected to the output transistors, and the output transistors. After re assembly the bias was checked and it was spot on. Sounded smashing, but i didn't want to see one again lol.
I literally had exactly the same amp (but in silver) on my bench this morning with exactly the same fault..... I thought that I would give it a go and look at that same board. I managed to get it out by just removing the speaker output board and 3 screws from the back then the cables and the four screws holding the board in place..... JACKPOT, the 7815 had literally blown itself to pieces. Having one in stock I fitted it and checked the other regs and all were fine. Feeling well pleased with myself (as I got the amp for free!) I re-assembled it and switched it on. It powered on and I waited.... It seemed to be ok then shut down just as it had originally. I removed the board again and all the components are still OK. Oh well you win some you lose some. Nice video. Now the big question is can I be bothered delving into this amp or not 🙂
nice! that looks really similar to mine though mine has alot more daughter boards to remove :) mine has been working fine for quite a long time, now that it is in an enclosed cabinet I am going to put a exhaust fan over it (the back of the cabinet is open. hopefully that will keep things from getting too hot. great video thanks for sharing!
Great vid. Big thanks. Just hoping my vintage AVC-A1XVA monster that I have had for nearly 13 years doesn't fail like this. At 44kg, It's too heavy to lift !
i bought an iron of aliexpress. but got the 110v for 220v. oh baby that tip glows bright orange.Thanks for vid. it seems you got lucky getting to those blown resistors real quick. It's like you have another special sense. nice one.
I have exactly the same issue on my denon AVR 110. I opened it up and its all greek to me until I found you! I am not sure I could put it all back together!! Yikes. Ill give an update! Thank you for your expertise! Maybe its time to upgrade to the old tube amps now!
Nice one. I had the lid off my Denon AVR-E400 a few weeks back investigating an issue.. Even worse to disassemble- the HDMI digital input board was connected to two other boards with multi pin connectors in a few different positions.. making a sort of "cube" of hard-connected boards.. what a pain. Their remote control app is garbage too, not buying Denon again. Going to replace the thing soon.
Denon is one of those brands I hate to work on. I currently have one on my bench with a blown L channel, usually in that case I'll recommend a full upgrade of the output and bias transistors based on the latest service bulletin. Overall extra cost of parts and little extra labour involved make it an easy sell if it will last longer.
Problem is, if any company were to try to break out of the race to the bottom, and make their receiver 25% more expensive than their competitors on the basis that it was service-friendly, they'd end up losing all their market share. Don't blame Denon, blame the buying public. The companies that wind me up are the ones who do charge more than anyone else for the same thing and *still* make their products unfriendly to service. Apple I'm looking at you.
Reason they make them so hard to work on? It's all about the $$$$. Either pay tons of money to have it repaired, or replaced. Such as everything today. Give me the old mechanical washers and dryers. And other appliances. Toothbrushes are amazing. I use them to clean fan grills that I cannot submerge in soapy water. Because the motor and wiring is attached. Just a damp toothbrush or paintbrush.
Good job. Sony receiver had a similar design. To deoxit 2 tone controls had to remove many screws, pull off the front panel and remove 2 circuit boards and disconnect 2 connectors just to get to them.
I've come across several of these troublesome designs and wished they had a diagnostic port or at least display error codes on the front panel. Why not right? Some of the higher end ones cost near the price of a new car! Thanks for sharing your findings.
+Ron - I wonder if this thing had a diagnostic mode which would display an error code. Usually you have to press a certain button combination at power-on to enter it. Might have saved our hero some more gray hairs if this was available.
Hi Dave, great video! I have an AVR-3312ci that is doing essentially the same thing. Power on, green flash every second for a-few seconds, then it "reboots" and does the same thing. No red ring though, it's always green, and the diagnostic menu shows "NO PROTECT" in the protection history. This unit seems to be a-bit of an older design than the AVR-2307 (different board layout, etc). Do you think the power supply regulators could be the issue with the AVR-3312ci also?
My Onkyo preamp has the same mess inside. It gives me the feeling that those units are patched up with new features over and over and over again year after year, never seeing a proper re-design.
A +20v and -15v supplies on an opamp do not affect its linearity, assuming 35v across the device is not beyond the abs max rating. They can be different voltages, it only makes the output stage clip asymmetrically. The input stage uses current sources to bias the input transistors so they don’t ‘feel’ the supply voltages (unless they’re very low or beyond abs max). Also I doubt there’s any sophisticated fault detection on the +/-15v rails. Maybe a basic min voltage check. It’s possible the 7815 output is shorted to the input. I wonder what those 2 ohm (0.22 ohm?) resistors are for. They’re not feedback resistors bc you have fixed regulators. Are there 2 positive regs? Current sharing resistors?
Okay so I have a similar unit. Has 4 power regulators on the heatsink. 15 pos, 15 neg, 12 and 5 volts. I replaced the 15 pos but still have the same problem. Looking at your technique for bypassing the regulator. Can you explain in a bit more detail how to do that. What are the connections and what power do I need. Thx
Love your perfect diagnosis for every fault, good work. I have a demon avr 4308 no sound form speakers but every other thing works alright. Please do you have a solution? Thanks.
What I did on my solder sucker is to cut a notch in the tip to account for the soldering iron or you can cut the tip at an angle so you don't have to be straight up and down to get the maximum suction.
Love the hunt of finding problems in a comex te River like this, interesting fun learning experience and detective work. Just fixed an NAD 7155 receiver making high pitched sequel sound, was a 2 1/2 day interesting hunt to fix. Sounds great now with one new transitive in pre amp and a few capacitors and three bad resistors.
HELP, PLEASE. I am working on one of these with the same layout and the same symptoms. I replaced the same resistors. The problem is that there is not enough voltage getting to the 15 and -15 regulators, its like 2volts. The diodes check out good. Any suggestions??? FYI, love the channel. Great videos!
I wonder if you could cut the bottom of the chassis out to get access to the bottom board. There are many tools and methods available that may make cutting thru the thin plate a feasible alternative.
It's funny you should say that. Back in the 90s (last decade for serviceable electronics) I remember Technics receivers had a bottom panel that could be cut out and flipped up side down and the technician would add 1 or 2 screws to hold the bottom panel in. Granted it was only to the output channel side but still better than disassembling the whole thing.
Hi there, I have a brandnew Marantz SR7015 and it shuts down on me. It’s not heat management , I replaced the wires, the ARC hDMI cable , and and factory reset , after factory reset it holds up for 2 hours and then it goes to protection mode , any idea ? Appreciate any info .
@@12voltvids haha, my man ! :)) ( i love watching your videos, thank u for your patience and time for explaining step by step all the electrotechnics involved, it amazes me u cleverly and logically know ur "circuits" pretty well sir !
@@Mihai092 truth be known I have forgotten much of it. I left the repair business in 2003 and went into a totally different industry. When I left I promised myself I would never work on electronics again. Managed to stay away for 9 years. Picked up the soldering iron as a favor for a friend and made a stupid video of the repair and put it on CZcams and the rest is history. Seems that there are a few people that still want to fix their old units and I have enough stuff of my own I have collected to keep me busy on my days off.
@@12voltvids i can imagine why u left, or at least i guess, im an Electrician myself but working within a 0.08/10kv electrical substations that powers up the tramway, transforming and lowering high currents from AV to DC, machines that acts like a big switch in case of overload to a certain amp 1500-2000. Not so much minimal electrotechnics in there, maybe on the automatic side of it and protections, relays, auxiliar side, batteries, etc, in rest more mechanics but i like that too.. i like doing stuff with my hands, i wouldnt imagine myself sitting in a chair not being in a team, working.. socializing, laughing. Im really noob in soldering, i first picked up the soldering iron when i was 8, i saw my dad repairing my nintendo ( he's an electrician too ) and i wanted to be like him ( ended up wrecking the gamepad that was trying to repair ).. since then i always had this passion for electronics. I just wish he would had/ share this kind of ur kindness, patience, approach and passion towards letting me know stuff when i was all over him.. i was always eager to learn but i guess he was too tired by this society. Anyway sorry for writing so much personal stuff and bad english :)) , u seem like a really kind man. Would ask for 1 more minute of your time, what do you think of nowadays Denon build quality, maybe compared to other receivers expecially on the low-entry.. i plan to buy a receiver for a 7.1 setup, i guess u saw some stuff opening so much cases :)) Thanks for your time and your response !
After seeing my amp taken apart like that , I'd rather buy a new one lol. I'm very fortunate that my denon x4000 and denon 3313UD still looks brand new always have left on stand by not to kill capacitors and always covered when not in use. If I'm lucky i get to watch a movie or two once a week thanks to work and family life another thing that's saved it for so long.
These modern surround sound receivers are hard to work with, and are not very reliable in general as they get older: they seem like the most common broken item in any household. This brings me to a problem I have been having with my early 2000s Onkyo 5.1ch receiver, the TX-SR500. Here’s the issue. It seems that around 1/4 of the times I turn it on, the rear left channel does not engage right away. When this happens, I usually have to tap on the woofer cone of the speaker on that channel. This is annoying, because I happen to have speakers with non-removable grills: the grill fabric is just stretched over the front baffle, with the drivers mounted from the inside! (Sound familiar? Yup, they’re Paradigm atom V2s. Refoamed, of course.) I can only barely touch the surround of the speaker through the grill. If the channel still does not power up, the next thing I do it press the “speakers A” button around 10 times in rapid succession, then go back to tapping the cone. This usually always fixes the issue. Is this a fixable problem? What do you think it might be? Does this sound like a capacitor? A resistor? A bad solder? A lost cause??? If I get a new receiver, what do you recommend? Yamaha? Marrantz? Denon? Another Onkyo? (This is my second Onkyo to have a problem. The first one was worse, it just acted like it wasn’t even plugged in. It was. I checked.) I will probably buy an older used product, to save money and materials. They usually work fine. My research has led me to believe that Yamaha lasts longer, but might be less clear with more midrange sound.
Hi there, 14 mins in and paused to write this comment as I have a Denon AVR-1910 which powers off after a 10-20 seconds with a blinking red power standby led, 0.5 sec intervals. Manual says either speaker / speaker connection issue or amplifier circuit has failed. I'm assuming the latter as I have disconnected all speakers and removed speaker cables, just powering the unit up with nothing connected and it does the same. When my speakers were hooked up I would get buzzing / interference sound start coming from them and then after a few seconds it would switch off and go into this blinking red power led phase. Hoping that this video will help direct me find the fault! I'm no expert at all, I don't know what resistor values should be should I need to check them but I have my trusted multimeter and have good experience with soldering (misspent youth chipping / jtagging consoles :-)) Seeing you move from the solder pump to the braid, lol, I can relate! I've never had a solder pump that can outdo the braid, they just aren't powerful enough when you can't get a snug fit up against the joint. PS: You don't use any flux I notice?
great video, I got a demon 1700 avr , very Lowe sound if you turn it up it cuts out and go's in to shut down, if it's on and I turn the bass knob it shuts down. I think it's the regulator to the two channels which could be at fault, what do you think. All the best Mark
I would check the amperage draw through the fusible resistors and on the 5V Circuit as well just to make sure nothing is getting too hot through them or there is not a partial short or anything causing that circuit to draw too much current. There is a reason why those resistors failed.
that is why i tend to salvage as much useful parts i can get from old boards because you can never known what will can save you a lot of time in a repair and you can pass the saving to the customer but in this trade you cannot save everything.
That crud surrounding the hand soldered connections is no clean flux. Most manufacturers will still wash it off their products, at least the IPC 610 rev. Class 3 assemblies. This product is somewhere in between Class 1 and 2.
bravo pour cette réparation. Cet appareil n'est pas facile à dépanner il faut tout désosser, j'en ai eu un avec les transistors de puissance en cc, les transistors coute une fortune, il a finit en pièces détachées .
Gawd, what a pfaff! No wonder these cost an arm and a leg to fix, and not being able to test your theory easily as it has to be mostly all put back together, its a case of the diagnosis has to be right the first time! My sympathies, entirely
Hi,I have a Sony STR-DG510 ,It has a very low hum when you turn it on,I mean very low,and when I record cassettes on my Pioneer the hum is also coming threw on the recording s.All the cables on my Pioneer are brand new,and also on my receiver. Thanks,Great channel 😎😎😎😎😎
wow ive seen one that looks similar to this one The one I had had more heatsinking though Sadly it was completely and utterly dead. fuse intact. just nothing worked. i ended up scraping it for parts since it had a lot circuit parts I could use.
I’d hate to think how many screws I’d have leftover after putting that thing back together. Absolutely ridiculous how modern kit is constructed in such a way as to make DIY repairs either impossible or awkward to the point of wanting to throw the bloody thing across the room and out the window; the consequence of which being an expensive item is likely to end up as a very ugly door-stop unless you can DIY or have access to a technician willing to do repairs at a price that is finically viable (ie less than the cost of replacing the unit in question)!
Just wait until the next generation is made all of glass and glued together like a cell phone lol Think that stuff on the output transistor was from hand soldering with a organic flux?
I picked one of these up at my local goodwill yesterday. It is doing the same thing. How difficult would it be for someone who has never done anything like to see if the cause is the same and if so do the repair?
@@12voltvids I do not but it would be a good idea for me to get them since I sell video games and being able to replace dead batteries on old pokemon games would be a good thing for me to be able to do.
The problem with these units being so hard to disassemble is you can't power them up and do any dynamic checks when you can get at stuff. You pull them apart, check and repair what's obvious and then cross your fingers. I've had to pull these things apart and re-assemble them 2 and 3 and 4 times sometimes. What a PITA. The last Denon receiver I repaired had a bad 7812 regulator (insulated plastic package of course i didn't have in stock) and a bad DSP flat pack that had a shorted audio mute line. I had to actually put the boards back together minus the chassis to power it up and find that problem. Denon probably makes test jig's for these but only factory authorized shops get them along with schematics. Lucky bastards.
Yes and now you know why so many shops refuse to service them. They are not the only ones making PITA equipment. Most of it is like this now and I am more likely to walk than fix it.
@@12voltvids I don't blame you. I got out 25 years ago when many tv manufacturers went the way of board swapping instead of component-level repair. You can still service most anything but it isn't profitable anymore. I repair equipment for friends and my own stuff but that's it. Nice work though, kudos for having the patience to do such tedious work!
Thank you and what I did rather than taking the whole thing apart which looks like a major pain in the ass is I took a small Dremel saw and dremeled a little square hole out on the bottom and just worked on it from within that hole which was so much easier and now my receiver works great
What an interesting statement. The manufacturers don't want these repaired. We are facing an environment crisis, that we may not recover from, and these companies promote waste. This has to change and very soon. I appreciate more than ever the quality electronics from the 1970's and 1980's. A person such as yourself could fix almost any electronics from this era. God bless.
Agree there are speakers tube amps turntables from way back when that out last morden day equipment. FACT another thing is how you use and look after it can play a major part also. Im lucky my home cinema i put together in 2012 is all in perfect working order. And was not cheap £8000+ made me give it that loving touch 😂😂😂
Sadly, you're correct and this is the case on almost every product. Even basic ones. I bought a manual can opener that cracked the very first can I tried to open.
It's true but hdmi arc is convenient to have, and room correction etc. It's sound united setting the trend for expensive electronics to be junk in reliability just to save a buck.
I tried explaining this fact about the environment to David Pogue and Scientific American, unfortunately, they are too tied up in their politics to examine reality.
Superb troubleshooting and repair on such a complex unit. Very well done! Very impressed.
Hi Dave, I just want to thank you for all that you do on your channel. By following along with your troubleshooting procedures I was able to fix my Yamaha A-S500 amplifier yesterday with an intermittent output on the right channel. I tracked it down to one of the protection relays and after re-flowing the solder connections it now sounds as good as when it was new. Keep the repair videos coming! :)
Good Job as everytime! And again a happy owner who can use his device for many years to come.
I have a Denon 1908 that had gone into fault and the client just told a colleague to take it away! The coaxial feed from a Skybox at the head end wouldn't work via a converter. Skyboxes used to only have full surround from their digital outs. Long story short - it finally landed in my lap after everyone else had given up (It was an AV installer company with no repair engineer). It just needed a factory reset!! I still have it as my home cinema set up. I had an issue a few years back in which it literally Screeched at a high level, moving the input leads cleared it. When I had lot's of time I decided to re-solder them, but they were fine! But then I saw that a Single strand of speaker wire was touching the main body, I changed to Banana plugs and it's been great ever since! These designers go to the pub each night and come up with more creative ways to make equipment non serviceable. And have a good laugh, no doubt. Unfortunately - the last laugh is Ours! Well done!!
Knowledge, patients and expertise in your work.👍👍
Your vids give me confidence to go gut my Onkyo receiver, which has certain 'audio modes' failing and randomly clicks relays from time to time. :)
Got my AVR-589 fixed, thank you! It was the -15v (7915 regulator) on that little power supply. Intermittent for the last few years and it finally fully failed a couple days ago.
I really enjoy and have learned a lot from your vids Dave. I have an 1803 on the bench right now...easy diagnosis as the previous owner shorted the center channel and blew the output transistors...The darlington is being replaced too because it is out of tolerance, but couldn't find the OEM, so I had to research for an equal...pain in the butt! At least taking the boards out gave me an excuse to completely clean the unit.
Well done. The PDFs of most service manuals for Denon (Pioneer, Onkyo, etc) A/V units are readily available on the internet. These units usually offer a diagnostic mode that will display a message or give a code for the type of fault shutdown (DC voltage, short circuit over current, etc).
By studying the schematic, you can narrow down to the faulty block or component. The various power feeds can be disconnected which can help isolate the problem down to a specific board, e.g. remove power from main amp board and unit powers up OK means the fault is on the main amp board. There may be safety interlocks between boards - so this method may not always work.
wow now that denon probably had enough screws to put up drywall in two rooms you get the very pateient person award . the last time I saw something with this many screws was a huge masterwork reciever with quadrophonic and there were over 55 screws holding everything in place good job as always nothing bad ever stands a chance to win with you on the job bravo
good job on the repair. thanks for sharing
Good job. My days of working on circuit boards and systems is over now - but it's nice to see someone who knows their trade doing it well!
Impressive. Glad I found your channel. So much knowledge.
You had to work for this one!
Good job I learned alot watching you with this one!
👏👏👏👍
this is a good video, i miss those old school repairs on new one chip electronics, they just making them for one time use
great job as always each video is a new adventure with great gear and the end result is always the same you make the gear like new thank you for sharing this
I have actually seen this same stuff and I am pretty sure it was solder resin used during assembly... it is almost the same as that circuit glue you have talked about ... over the years it becomes conductive... thus triggering the protect circuit ... I have a neighbor that had one for approximately 15 years and it was triggering the protect circuit... cleaned the entire board with isopropyl alcohol removing the solder resin used during the manufacturing process... and just to make sure re-flowed the output transistors... no more circuit protection kicking in ... I suppose after washings during production the solder rinsing fluid becomes too saturated with resin to fully clean the resin and over time it becomes conductive enough to trigger the protection circuit in all honesty I believe that was the problem and that's the crud you saw ... I am not certain but I think the power transistors are solder by hand and they don't clean the resin afterwards... and over the years it becomes conductive enough to trigger the protection circuit to activate... my neighbor's unit functions perfectly... during the cleaning the resin was very brown as it was absorbed by the old towel if I understand correctly the resin is a very mild for acid to clean the surfaces as they are soldered in place and that explains why it becomes slightly conductive as time passes... I recently had the same trouble with my computer board ... it wouldn't even POST (power on self test) prior to that I had a hard drive (4 total) that Windows kept popping up messages cache couldn't be read data maybe lost ... and it would disconnect from the drive completely.... after I did the same method cleaning the entire motherboard it has not given any messages about not being able to read cache from or to the drive and it posts EVERY TIME NOW as well ... I am very convinced that the traces of solder resin will cause problems over time... most devices these days use EXTREMELY small current signals that can be wiped out or at least be undetectable not to mention how the tiniest currents these signals push through to other chips and circuits anyway hope this helps someone that can't find any bad components yet the device still won't work correctly
That thing scares the crap outta me. Well done sir!
Thank you for this repair footage, I have the same problem on my Denon AVR2307 AV receiver, hopefully, I can fix this too as your suggestions. 2 fusible resistor 0.22 Ohm and 15V regulator LM 7815. Two thumbs up!
I love your videos. I learning more and more. Congratulations from BRAZIL. ps I remember my late father-in-law who was doing this kind of repair.
Wow. that much disassembly looks like a nightmare. I have a Denon that one channel is not working. I think it is probably cheaper to buy a new unit. This one is 6 years old. I have to assume that the cost of all that work would be more than half of what a new unit would cost, (assuming about $500 is my budget.) Great work and patients. You are a master electronic technician.
I have a Goldstar brand amp that I assume is from the mid-80s. I picked it up because I liked the looks and it was just a buck. It has a 1.5 amp fuse inside that looks like it got a little too tired one day. No smoked glass though. It also has a whopping 15 amp fuse that I popped when I flip the voltage switch to 240. The power transformer made an interesting hum before the fuse went
great video and good to see cat at end of intro
Just like all new electronics. They really don’t want you to repair anymore. They make their money selling new ones. Excellent repair video as always
Great diagnosing as always. Being I have several Denon's with one being an AVR2308CI, it's good to know if that problem ever crops up! Thanks!!
learnt many things from ur videos. its very informative.
Sir, you are absolutely genius. Yours videos so detailed and helpful for me. Love from India. Keep it up.
Dave, i feel really sorry for you as i repaired the same unit back in 2015 and i hated the design :-(
On mine, one channel had blown up taking nearly every part connected to the output transistors, and the output transistors.
After re assembly the bias was checked and it was spot on.
Sounded smashing, but i didn't want to see one again lol.
I used to dread Yamaha for the same reason
I literally had exactly the same amp (but in silver) on my bench this morning with exactly the same fault..... I thought that I would give it a go and look at that same board. I managed to get it out by just removing the speaker output board and 3 screws from the back then the cables and the four screws holding the board in place..... JACKPOT, the 7815 had literally blown itself to pieces. Having one in stock I fitted it and checked the other regs and all were fine. Feeling well pleased with myself (as I got the amp for free!) I re-assembled it and switched it on. It powered on and I waited.... It seemed to be ok then shut down just as it had originally. I removed the board again and all the components are still OK. Oh well you win some you lose some. Nice video. Now the big question is can I be bothered delving into this amp or not 🙂
nice! that looks really similar to mine though mine has alot more daughter boards to remove :) mine has been working fine for quite a long time, now that it is in an enclosed cabinet I am going to put a exhaust fan over it (the back of the cabinet is open. hopefully that will keep things from getting too hot. great video thanks for sharing!
Great vid. Big thanks. Just hoping my vintage AVC-A1XVA monster that I have had for nearly 13 years doesn't fail like this. At 44kg, It's too heavy to lift !
i bought an iron of aliexpress. but got the 110v for 220v. oh baby that tip glows bright orange.Thanks for vid. it seems you got lucky getting to those blown resistors real quick. It's like you have another special sense. nice one.
That's a quality vid. Really enjoyed this one🔟🔟👍
Great repair!
Thanks for the video. I have a not working AVR 2800, 19 years old and now I know I'll throw it to the dumpster.
Schematic? I don't need no frikken schematic!!! Awesome repair
I have exactly the same issue on my denon AVR 110. I opened it up and its all greek to me until I found you! I am not sure I could put it all back together!! Yikes. Ill give an update! Thank you for your expertise! Maybe its time to upgrade to the old tube amps now!
Vacuum tubes.
Where everyone can be a Master tech.
Nice one.
I had the lid off my Denon AVR-E400 a few weeks back investigating an issue.. Even worse to disassemble- the HDMI digital input board was connected to two other boards with multi pin connectors in a few different positions.. making a sort of "cube" of hard-connected boards.. what a pain.
Their remote control app is garbage too, not buying Denon again. Going to replace the thing soon.
Denon is one of those brands I hate to work on. I currently have one on my bench with a blown L channel, usually in that case I'll recommend a full upgrade of the output and bias transistors based on the latest service bulletin. Overall extra cost of parts and little extra labour involved make it an easy sell if it will last longer.
Great video ,thanks for sharing , gonna have a go on my Denon POA 2800 now :)
Problem is, if any company were to try to break out of the race to the bottom, and make their receiver 25% more expensive than their competitors on the basis that it was service-friendly, they'd end up losing all their market share.
Don't blame Denon, blame the buying public.
The companies that wind me up are the ones who do charge more than anyone else for the same thing and *still* make their products unfriendly to service. Apple I'm looking at you.
Jason J make it easier to repair *without driving costs* = put your competitors out of the market.
Thats what I call A Nightmare Electronic device. Always enjoy your videos. Thumbs Up !
I generally avoid all these AV receivers. They are not enjoyable to repair, and I don't need to prove to anyone I can fix them. I would rather not.
Thanks for guys like you. I will perform a similar task on a avr 3311
Good job Dave I like your work then you have a conclusion the unit.
Amazing engineer 👏
Did you have any screws left over? Great job.
You are brilliant
Always love your videos. I have a sony rack mount mini disc player that doesn't work. Have you ever worked on one of those?
well done,got there in the end
Reason they make them so hard to work on? It's all about the $$$$. Either pay tons of money to have it repaired, or replaced. Such as everything today. Give me the old mechanical washers and dryers. And other appliances. Toothbrushes are amazing. I use them to clean fan grills that I cannot submerge in soapy water. Because the motor and wiring is attached. Just a damp toothbrush or paintbrush.
Good job. Sony receiver had a similar design. To deoxit 2 tone controls had to remove many screws, pull off the front panel and remove 2 circuit boards and disconnect 2 connectors just to get to them.
Very interesting video, thanks for posting.
I've come across several of these troublesome designs and wished they had a diagnostic port or at least display error codes on the front panel. Why not right? Some of the higher end ones cost near the price of a new car!
Thanks for sharing your findings.
+Ron - I wonder if this thing had a diagnostic mode which would display an error code. Usually you have to press a certain button combination at power-on to enter it. Might have saved our hero some more gray hairs if this was available.
Interesting video, definitely is not for the faint hearted!
Hi Dave, great video! I have an AVR-3312ci that is doing essentially the same thing. Power on, green flash every second for a-few seconds, then it "reboots" and does the same thing. No red ring though, it's always green, and the diagnostic menu shows "NO PROTECT" in the protection history. This unit seems to be a-bit of an older design than the AVR-2307 (different board layout, etc). Do you think the power supply regulators could be the issue with the AVR-3312ci also?
My Onkyo preamp has the same mess inside. It gives me the feeling that those units are patched up with new features over and over and over again year after year, never seeing a proper re-design.
You should see my old Harmon Kardon. Even I am nervous going into that one. Some day I might actually fix it.
since your in washington would you happen to have a speaker terminal block for a carver model hr-805?? its the main a and b speaker block
A +20v and -15v supplies on an opamp do not affect its linearity, assuming 35v across the device is not beyond the abs max rating. They can be different voltages, it only makes the output stage clip asymmetrically. The input stage uses current sources to bias the input transistors so they don’t ‘feel’ the supply voltages (unless they’re very low or beyond abs max).
Also I doubt there’s any sophisticated fault detection on the +/-15v rails. Maybe a basic min voltage check. It’s possible the 7815 output is shorted to the input. I wonder what those 2 ohm (0.22 ohm?) resistors are for. They’re not feedback resistors bc you have fixed regulators. Are there 2 positive regs? Current sharing resistors?
I don’t envy repairing this horrible unit.
Well done.
Okay so I have a similar unit. Has 4 power regulators on the heatsink. 15 pos, 15 neg, 12 and 5 volts. I replaced the 15 pos but still have the same problem. Looking at your technique for bypassing the regulator. Can you explain in a bit more detail how to do that. What are the connections and what power do I need. Thx
Love your perfect diagnosis for every fault, good work. I have a demon avr 4308 no sound form speakers but every other thing works alright. Please do you have a solution? Thanks.
What I did on my solder sucker is to cut a notch in the tip to account for the soldering iron or you can cut the tip at an angle so you don't have to be straight up and down to get the maximum suction.
Love the hunt of finding problems in a comex te River like this, interesting fun learning experience and detective work.
Just fixed an NAD 7155 receiver making high pitched sequel sound, was a 2 1/2 day interesting hunt to fix. Sounds great now with one new transitive in pre amp and a few capacitors and three bad resistors.
just a quick question what wattage iron do you have?
HELP, PLEASE. I am working on one of these with the same layout and the same symptoms. I replaced the same resistors. The problem is that there is not enough voltage getting to the 15 and -15 regulators, its like 2volts. The diodes check out good. Any suggestions???
FYI, love the channel. Great videos!
I wonder if you could cut the bottom of the chassis out to get access to the bottom board. There are many tools and methods available that may make cutting thru the thin plate a feasible alternative.
It's funny you should say that. Back in the 90s (last decade for serviceable electronics) I remember Technics receivers had a bottom panel that could be cut out and flipped up side down and the technician would add 1 or 2 screws to hold the bottom panel in. Granted it was only to the output channel side but still better than disassembling the whole thing.
Hi there, I have a brandnew Marantz SR7015 and it shuts down on me. It’s not heat management , I replaced the wires, the ARC hDMI cable , and and factory reset , after factory reset it holds up for 2 hours and then it goes to protection mode , any idea ? Appreciate any info .
would you get about 7X 65 watts out of that or not?
You can't win on consumer and it will only get worse as complexity goes up and price goes down. Any commercial units for the home out there?
So how many spare screws after reassembled?
Hasn't gone back together yet. I could leave half of them out and nobody would know.
lol
@@12voltvids haha, my man ! :)) ( i love watching your videos, thank u for your patience and time for explaining step by step all the electrotechnics involved, it amazes me u cleverly and logically know ur "circuits" pretty well sir !
@@Mihai092 truth be known I have forgotten much of it. I left the repair business in 2003 and went into a totally different industry. When I left I promised myself I would never work on electronics again. Managed to stay away for 9 years. Picked up the soldering iron as a favor for a friend and made a stupid video of the repair and put it on CZcams and the rest is history. Seems that there are a few people that still want to fix their old units and I have enough stuff of my own I have collected to keep me busy on my days off.
@@12voltvids i can imagine why u left, or at least i guess, im an Electrician myself but working within a 0.08/10kv electrical substations that powers up the tramway, transforming and lowering high currents from AV to DC, machines that acts like a big switch in case of overload to a certain amp 1500-2000. Not so much minimal electrotechnics in there, maybe on the automatic side of it and protections, relays, auxiliar side, batteries, etc, in rest more mechanics but i like that too.. i like doing stuff with my hands, i wouldnt imagine myself sitting in a chair not being in a team, working.. socializing, laughing. Im really noob in soldering, i first picked up the soldering iron when i was 8, i saw my dad repairing my nintendo ( he's an electrician too ) and i wanted to be like him ( ended up wrecking the gamepad that was trying to repair ).. since then i always had this passion for electronics. I just wish he would had/ share this kind of ur kindness, patience, approach and passion towards letting me know stuff when i was all over him.. i was always eager to learn but i guess he was too tired by this society. Anyway sorry for writing so much personal stuff and bad english :)) , u seem like a really kind man. Would ask for 1 more minute of your time, what do you think of nowadays Denon build quality, maybe compared to other receivers expecially on the low-entry.. i plan to buy a receiver for a 7.1 setup, i guess u saw some stuff opening so much cases :)) Thanks for your time and your response !
Hi Dave, I have the same model, no sound output but powers on screen & everything works ostensibly. What do you think it is?
Thanks
Good skill,,,👍
After seeing my amp taken apart like that , I'd rather buy a new one lol. I'm very fortunate that my denon x4000 and denon 3313UD still looks brand new always have left on stand by not to kill capacitors and always covered when not in use. If I'm lucky i get to watch a movie or two once a week thanks to work and family life another thing that's saved it for so long.
Nice one
These modern surround sound receivers are hard to work with, and are not very reliable in general as they get older: they seem like the most common broken item in any household. This brings me to a problem I have been having with my early 2000s Onkyo 5.1ch receiver, the TX-SR500.
Here’s the issue. It seems that around 1/4 of the times I turn it on, the rear left channel does not engage right away. When this happens, I usually have to tap on the woofer cone of the speaker on that channel. This is annoying, because I happen to have speakers with non-removable grills: the grill fabric is just stretched over the front baffle, with the drivers mounted from the inside! (Sound familiar? Yup, they’re Paradigm atom V2s. Refoamed, of course.) I can only barely touch the surround of the speaker through the grill.
If the channel still does not power up, the next thing I do it press the “speakers A” button around 10 times in rapid succession, then go back to tapping the cone. This usually always fixes the issue.
Is this a fixable problem? What do you think it might be? Does this sound like a capacitor? A resistor? A bad solder? A lost cause???
If I get a new receiver, what do you recommend? Yamaha? Marrantz? Denon? Another Onkyo? (This is my second Onkyo to have a problem. The first one was worse, it just acted like it wasn’t even plugged in. It was. I checked.) I will probably buy an older used product, to save money and materials. They usually work fine. My research has led me to believe that Yamaha lasts longer, but might be less clear with more midrange sound.
Hi there, 14 mins in and paused to write this comment as I have a Denon AVR-1910 which powers off after a 10-20 seconds with a blinking red power standby led, 0.5 sec intervals. Manual says either speaker / speaker connection issue or amplifier circuit has failed. I'm assuming the latter as I have disconnected all speakers and removed speaker cables, just powering the unit up with nothing connected and it does the same. When my speakers were hooked up I would get buzzing / interference sound start coming from them and then after a few seconds it would switch off and go into this blinking red power led phase.
Hoping that this video will help direct me find the fault! I'm no expert at all, I don't know what resistor values should be should I need to check them but I have my trusted multimeter and have good experience with soldering (misspent youth chipping / jtagging consoles :-)) Seeing you move from the solder pump to the braid, lol, I can relate! I've never had a solder pump that can outdo the braid, they just aren't powerful enough when you can't get a snug fit up against the joint.
PS: You don't use any flux I notice?
the VR that feed the OP-AMPS go bad causing that shut down. I worked on those receivers for a company. It was a pain in the rear.
great video, I got a demon 1700 avr , very Lowe sound if you turn it up it cuts out and go's in to shut down, if it's on and I turn the bass knob it shuts down. I think it's the regulator to the two channels which could be at fault, what do you think. All the best Mark
Don't have the foggiest.
I would check the amperage draw through the fusible resistors and on the 5V Circuit as well just to make sure nothing is getting too hot through them or there is not a partial short or anything causing that circuit to draw too much current. There is a reason why those resistors failed.
Probably the first guy that "tried" to fix it, because I am not the first one into it. It was already condemned by another shop.
those were tiny resistors, probably rated for exactly the power they were wasting, its an engineered failure point.
that is why i tend to salvage as much useful parts i can get from old boards because you can never known what will can save you a lot of time in a repair and you can pass the saving to the customer but in this trade you cannot save everything.
That crud surrounding the hand soldered connections is no clean flux. Most manufacturers will still wash it off their products, at least the IPC 610 rev. Class 3 assemblies. This product is somewhere in between Class 1 and 2.
I never did learn the resistor color bars and I studied engineering.
Thank you sir i am banging my head over a denon same issue
bravo pour cette réparation. Cet appareil n'est pas facile à dépanner il faut tout désosser, j'en ai eu un avec les transistors de puissance en cc, les transistors coute une fortune, il a finit en pièces détachées .
Gawd, what a pfaff! No wonder these cost an arm and a leg to fix, and not being able to test your theory easily as it has to be mostly all put back together, its a case of the diagnosis has to be right the first time! My sympathies, entirely
not sure i'd remember how to put this one back together lol
Hi,I have a Sony STR-DG510 ,It has a very low hum when you turn it on,I mean very low,and when I record cassettes on my Pioneer the hum is also coming threw on the recording s.All the cables on my Pioneer are brand new,and also on my receiver. Thanks,Great channel 😎😎😎😎😎
There is a simple explanation to your hum. It doesn't know the words!
Dude,this isn’t a joke,can you help me or no??
@@johnd1616 ground loop?
wow ive seen one that looks similar to this one The one I had had more heatsinking though
Sadly it was completely and utterly dead. fuse intact. just nothing worked. i ended up scraping it for parts since it had a lot circuit parts I could use.
Hi Dave, I'm guessing your screwdriver is a little half ounce over on the back end, right? 😂Keep up the good content, Bud. Best Wishes.
I’d hate to think how many screws I’d have leftover after putting that thing back together. Absolutely ridiculous how modern kit is constructed in such a way as to make DIY repairs either impossible or awkward to the point of wanting to throw the bloody thing across the room and out the window; the consequence of which being an expensive item is likely to end up as a very ugly door-stop unless you can DIY or have access to a technician willing to do repairs at a price that is finically viable (ie less than the cost of replacing the unit in question)!
Awesome
Just wait until the next generation is made all of glass and glued together like a cell phone lol
Think that stuff on the output transistor was from hand soldering with a organic flux?
Sir how many volt resistance have you change
Not exactly very eco friendly if you can't service these more land fill!
I've Denon 4311ci it shows DSP 01 error no audio out (analog and HDMI I/P), rest of the things working fine how to fix this?
I picked one of these up at my local goodwill yesterday. It is doing the same thing. How difficult would it be for someone who has never done anything like to see if the cause is the same and if so do the repair?
Hard to say. Do you have a meter and soldering iron.
@@12voltvids I do not but it would be a good idea for me to get them since I sell video games and being able to replace dead batteries on old pokemon games would be a good thing for me to be able to do.
Denon know it was that hard to work on....geeez
The problem with these units being so hard to disassemble is you can't power them up and do any dynamic checks when you can get at stuff. You pull them apart, check and repair what's obvious and then cross your fingers. I've had to pull these things apart and re-assemble them 2 and 3 and 4 times sometimes. What a PITA. The last Denon receiver I repaired had a bad 7812 regulator (insulated plastic package of course i didn't have in stock) and a bad DSP flat pack that had a shorted audio mute line. I had to actually put the boards back together minus the chassis to power it up and find that problem. Denon probably makes test jig's for these but only factory authorized shops get them along with schematics. Lucky bastards.
Yes and now you know why so many shops refuse to service them. They are not the only ones making PITA equipment. Most of it is like this now and I am more likely to walk than fix it.
@@12voltvids I don't blame you. I got out 25 years ago when many tv manufacturers went the way of board swapping instead of component-level repair. You can still service most anything but it isn't profitable anymore. I repair equipment for friends and my own stuff but that's it. Nice work though, kudos for having the patience to do such tedious work!
@@vilhjalmurtheviking4617 When I see units like it reminds me why I got out.
Thank you and what I did rather than taking while unit apart which looks like pain in ass is I took a
Thank you and what I did rather than taking the whole thing apart which looks like a major pain in the ass is I took a small Dremel saw and dremeled a little square hole out on the bottom and just worked on it from within that hole which was so much easier and now my receiver works great