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Polk PSW505 Sub Woofer - Troubleshoot & Repair
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- čas přidán 27. 06. 2020
- This video will show the repair of three different problem areas found in the Polk PSW505 that was presented to me.
In a previous career I spent 25 years in the high-end audio sales and service business. A friend of mine asked me to take a look at his Polk PSW505 sub woofer that was generating loud noises and powering off. After doing a bit of research on the internet for a quick fix I found that a lot of people out there were having a similar problem. The factory was no help in providing a schematic or offering the proper tech support that I was used to receiving "back in the day". Be patient! This will probably be not be a quick fix, but it can be done.
I hope this helps!
Regards,
Dennis
In this video I refer to two links.
Parts source:
www.digikey.com/
To decode the part number on a small SOT23 case transistor:
www.s-manuals.com/smd
This is one of the clearest and best produced explanations I've seen on YT for any topic. Bravo.
Thank you so much for your kind words! I try to pace my videos so beginners won't get lost, and "old pros" won't get bored.
I own this subwoofer and the amp also appears to be blown. No way do I have the know-how to do the troubleshooting and repair like you. Just wanted to say I'm amazed at your work, and that there are people out there with such a thorough understanding of these electronics systems. Love it.
I appreciate your comments. There are plenty of basic electronics videos on CZcams. Start with the easy stuff and work your way up. You'll be a troubleshooter before you know it!
18 cent part is causing the sub to turn off. Mind blowing. Thanks so much for this info. Won't need to buy a new sub woofer.
Thanks. Good luck with your repair.
Dennis, thank you so much for the time you put into recording your repair, editing, note taking, etc. For years I've been wondering why no one had done this long ago. These subs have been problematic for a very long time.
Thank you for your comments. It took longer to make the video than to do the repair!
My takeaway...... Replace all the capacitors on every board.
This is a very good fix it video, love that you added the parts list. Talk about piss poor caps! I own two of these subs, both committed suicide while not even being used, each pushing up daisies in their own strange ways. The first one died with a straight THUMP DC to the speaker, no audio output. The other one, similar to the one you worked on.
Sorry you had bad luck with two of these subs. Thanks for your comment about the parts list.
Mine died a few weeks ago. I just finished the repair. I scoped the 57VDC output from the power supply and it was an absolute mess. Lots of AC leakage. Broke out the ESR meter and there were a bunch of caps that were either flat out bad or very close to the edge of being out of spec. I wound up replacing all the electrolytic caps on all three boards with the exception of the large power caps. I used high quality Panasonics so hopefully this will last a a few more years. From troubleshooting to repair it was about three hours of my time and $25 at Digi-key.
Good for you. Persistence pays off!
You're a life saver, I have the same problem and since I don't have the knowledge and the testing equipment I'm going to try and replace the same parts as you and hope that it works. I'm quarantined anyway with nothing to do.
Thanks
Thanks and good luck to you!
Bought this sub (bought 2 of them) based on the 5star reviews. One arrived DOA and I was refunded, but they did not want the sub back. I found this video as I started to look for the potential for a repair and essentially get a free sub. Thanks for putting this content out there.
Your welcome. Good luck!
Excellent troubleshooting Dennis. I have one of these coming my way for repair, and this video will prep me for it.
Look up the data sheet for the driver IC and you will get a good sense of how the amp works (Class A design). Be patient and you will be successful.
I have had mine for about 2 years now and it just died in the middle of me watching a movie. I can try to take the time to tackle this repair but I'm not a big fan on working with capacitors and I'm not the best with electronics. This is a really good video that goes into great detail. Mr Miles are you up for challenge to get my psw505 up and running. I'm not sure if you have a repair shop but I'll send it off and pay you.
Excellent video. Your pace and the details are very helpful. I occasionally get these subwoofers in the shop I'm currently have a Polk on the bench. Was prepared to replace all small caps. See if my basic ESR pick things up as well as your more modern one.
Thanks. Please know that any ESR meter is better than no ESR meter! Good Luck.
One of the best videos I have seen on CZcams in a long time. Awesome work. I could never do it, so if you change your mind about doing repairs, I could send you my board and you could give me an estimate. :)
Thank you. I appreciate your comments. Getting back into the repair business would require creating a an entity, liability insurance, tax returns, etc. No thanks. I happy to share my knowledge. Find an electronics shop in your area and have them watch the video. I bet they will be able to fix your panel for a reasonable price.
saved me from trashing my 2 year old sub! Had the same zener diode burnt up, swapped it and works good as new
Thank you!!
Thanks for your feedback. That makes the time I spent making the video worthwhile! I'm guessing you made sure the large power resistors were soldered in properly. I think the fluctuation in the supply due to the bad joint on them is what caused the zener to pop.
@@dennisbsutube I did, the solder joints seemed to be fine, I will still keep an eye on it but hopefully all is good. Thanks again great vid
Great Video!! I have replaced several bad capacitors on the amplifier board and like yours, they are all the medium to small ones. I had to pull each one out to test it. I need to get one of those in circuit testers. I have almost gotten the woofer to work again, except the -57v rail of the power supply dips to -48v every few seconds and when it does that the amp shuts down. The +/- 180v square wave (PWM) primary to the switching transformer seems to get wonky when this happens. The +57 stays perfect during this time. Guess I will test those same caps you found bad on that board hoping that might work. The diodes are not cracked and loading resisters have good solder joints. I have never seen such a good troubleshooting video, I subscribed to see if you had more :) Thanks for all the time you put into this!
Thanks. I'm glad you are getting some good pointers from the video. I do wish Polk would release a schematic to help service shops repair their equipment. They are not making any friends the way they do business.
I am curious as to why the +57 volt side works well while the PWM gets "wonky". I would think the PWM should drive both sides of the supply. Your problem could still be in output section of the amp, drawing down the supply, but I would trouble-shoot the supply first.
If it helps, here is a link to the amp driver IC data sheet that shows a basic schematic of how the amp is put together.
www.infineon.com/dgdl/auirs2092s.pdf?fileId=5546d462533600a4015355bf314b15a3
Good luck,
Dennis
I have two of these and so far so good.
Thank you i replaced all the bad caps on my polk sub last year, but could not find the zener diode part number till no, awesome trick with the freeze spray
Always fun to pass on some of the tricks we used back in the day.
Thanks for this video! My just went dead (no power indication) and a pulsation sound from the speaker. Lets see what’s going on, I don’t see any fuse so probably will have to check the components as you did
Great Breakdown and Repair Job !!!!!!! Thanks on The Warnings ⚠️ Because Some People Think 🤔 Small Electronics Aren’t Dangerous ⛔️
Thanks. One must always respect the potential of switch-mode power supply, especially one with an AC cord.
I have two of these subs and both have tis exact same problem... I'm pretty handy and was thinking hopefully I could just replace a couple caps or something to fix it. After watching this I think I'm just gonna buy new ones lol
omg that is so much work, but if you have the time, the skills, the equipment, the energy, then sure why not. Mine just died a couple days ago. I may endup buying the whole amp plate
Great in depth review!
Much appreciated!
This tech is very good at what he does.
Thank you for the inputs sir..helps me a lot in troubleshooting the unit
Glad to help!
@@dennisbsutube thyank you sir
Excellent video, thank you.
Thanks! I'm glad you found it helpful.
I purchased this same unit and the amp was faulty. It died and I contacted Polk to see if they would help me. They refused to replace the amp because it was outside of warranty. There seems to be a lot of information about the problems these units have had online. I would not recommend purchasing one.
They do offer a replacement panel for $180. I'm going to simply repair it
Thanks for making this video. Very informative.
Glad it was helpful!
@@dennisbsutube Just curious, how much time did you spend on this repair? I have the same sub with the same issues. I'm tempted to just buy a new panel. They're about $220. It's been a great sub.
@@eggnogfrog One hour spent figuring out the circuitry, expected voltages, and generally how it worked (which is in the video). Troubleshooting one hour; replacing parts one hour.
@@dennisbsutube Nice! What's your hourly rate, and can I mail you my panel? :)
Ha... no thanks. My dance card is pretty full right now.
Incredibly informative. I replaced the caps on my amp board about 2 years ago, but now I've got an issue where the power supply is only putting out 14.4v. Debating whether I should buy an ESR meter or put that money towards an entirely new amp or subwoofer. Would like to save this one if I can.
If you only occasionally do troubleshooting, an inexpensive ESR meter is better than no meter. Search on eBay for : LCR-TC1 Transistor Tester ESR Capacitance Meter Electronic Component NPN PNP. About $25.00.
Is your main supply (+65 and -65) down to 14.4, or is the 15 volt supply low?
@@dennisbsutube Yeah, I'm thinking it's worth it. The 15v supply lines (+ and -) are exactly15v, but the +57 and -57 are +14.4 and -14.4
@@dirtfpv I have the exact same issue! Did you ever find a fix?
@@ehss192 I ended up buying a new one but I still want to work on fixing this one. I bought the esr meter though.
@@dirtfpv I see that same issue...the power supply output is at 14.4VDC when it is disconnected from the audio amp board (the 3 wire connector), but appears to be at +/- 47VDC when connected to the audio amp board. I'm wondering if it has some sort of current sensing feature that shuts down DC power output when there's no demand current.
You are the man.
Genius! Subscribed.
Thanks! I appreciate the positive feedback.
Thank you for posting this video. I used it to replace some bad caps on the power supply. Unfortunately, I didn't have +/- 57V output before and still don't, so I have to dig deeper. No obvious signs of burned components or bad solder joints. Just not sure how to test the other components.
If you are missing both the +/- 57V supplies you need to go to the beginning of the switch-mode circuit, usually just after a coil type transformer. You are better off troubleshooting this circuit cold (AC power cord disconnected) so you don't get shocked. The problem will most likely be an open semi-conductor or fuseable /power resistor. A tip would be to look up the part numbers on the Mosfets or other major semi-conductors, find the datasheets and hopefully an application diagram that will show you a schematic of how that component is typically used.
@@dennisbsutube I think I have a lack of knowledge about DC output from the power supply. When the power supply is disconnected from the audio amplifier at the 3-pin connection, I see only 14VDC on one leg. When I plug the power supply into the audio amp board, I see +/- 57VDC. However, if I disconnect that 3-pin connector from the audio amp board, DC voltage slowly fades away. Is there a current sensing feature that essentially shuts off DC output from the power supply if there's no demand load? If yes, then my power supply is working fine and the problem lies on the audio amp board.
At any rate, I still have the "heartbeat" after replacing all caps. I get a red power LED when the speaker is not attached; however, as soon as I attach the speaker, the power LED goes dark and the heartbeat returns.
Robert, disconnecting live power supplies to isolate problems is not a good practice, especially when dealing with switch-mode power supplies. Newer power supply designs can depend on feedback loops or an expected load to oscillate properly. You are always fine to check components when the main power source (AC) is disconnected, or live if you understand how to safely do that.
Please remember that the PSW505 also has an audio detection circuit that turns the amp on/off. This could also be the source of your problem. If there is a cap in this detection/switching circuit that is off spec, it could cause the heartbeat symptom that you are experiencing. As I recall, most of this circuit is on the main amp board. Pull that board, put it on your bench, and start testing the components on it. Do you have a component tester, multi-meter, or hopefully both?
@dennisbsutube Thank you, Dennis. Learned what a switch-mode power supply is and that is indeed why I'm seeing the DC volts drop when the power supply isn't connected to the amp board. I'll stab the back of the 3-pin connector for future measurements.
Replaced all the caps on the amp board but have pulled it and will learn more about testing the various components. I have an ESR meter and multimeter. Might consider getting a multi-component tester. I don't want this one to beat me!
I had the same problem with mine. One day I noticed the bass was lacking while watching a movie, and discovered the power light on the sub was off. I thought it was dead. Next time it was suddenly back on. A few weeks ago I noticed this howling noise coming from the sub, and had to unplug it to get it to stop. I replaced the connecting cables, tried a different outlet. It's completely dead now. I like their speakers. I've owned SDA 2A's, Monitor 10 B's; All of my speakers are Polks. But will never buy or recommend another Polk subwoofer.
Mine just took a dump, so doing the shady thing, I ordered another from amazon and just swapped out the electrical components and was going to return the dead one (I don't feel that bad, Polk should make a better product) and when I went to return it, they told me they would refund my money and told me I could trash it and not even bother returning it... So now I have two subs, one new and one that is doing this... So I guess I have no reason to not try and do this repair and see what happens... Thanks for the video
This guy is awesome !
Glad you found the video helpful. Thanks.
Nice video. Thanks for sharing. So what does the freeze spray show exactly? Can you turn a can of air upside down to achieve a similar effect?
The freeze spray trick is only used when you have a part, typically a semi-conductor, that consistently fails after a circuit has warmed up. The freeze needs to be instantaneous and extremely cold to shock the part back into a temporary working condition. If you have a can of compressed air that will expel freon when turned upside down it might work, using a can a freeze spray is the best option.
I have a Cambridge Audio Aero 9 sub which also has intermittent issues.
I can't for the will of trying and spending a few hrs researching, I just can't find schematic for it so I can trouble shoot for components.
Do you have any ideas with your knowledge on how I can start this on the right track.
I am a novice but have done small ish repairs so I can solder etc.
Cheers in advance
Haha here I was thinkin maybe I could fix this myself. Nope... Also, great video haven't seen an oscilloscope since my engineering school days. But I love the in depth analysis
Thanks. It's never too late to try.
Hey Denis good troubleshoot , wondering what website you were able to pull the values from the bad caps ? Is it the same link u provided on vid or did u have schematics
The values of a cap are printed on the cap itself. Example: 22uf 35V would be a 22 microfarad 35 volt capacitor. The link to Digikey is to give you a source to buy the parts.
Hello Dennis,
Happy new year.
First, thank you so much for great informative videos. I request your help for my sub repair.
My psw303 doesnt power up. I changed fuses 3 times but they keep blowing up as soon as i power it on. Can you please guide what i can do to solve this issue ?
Thank you in advance..
Fuses blowing instantly is most commonly caused by a shorted semi-conductor in the power supply or main power amp (pre-amp is probably okay). Disconnect the AC power to the unit, discharge the main capacitors, and check the diodes, rectifiers, power transistors, MOSFETs, etc. in the power supply and main amp. Do you have any test gear? A multi-meter (ohm meter) will be needed at a minimum. An electronic component tester can be purchased these days for under $25 that can also be a great help.
Hi Dennis , Im wondering if you can fix Definitive Technology BP-7001 SC's amplifiers?
Sorry, I retired from the repair business many years ago. I did find the following contact information for Definitive Technology. Hopefully they can steer you in the right direction.
Call: 1-800-228-7148 option 1 or Email: info@definitivetech.com
Great video but I think I'm just going to buy another sub. Next one definitely won't be a polk with how many 505s seem to go tits up after a few years. Unfortunately mine went out of warranty before it died. Sounded amazing before that. Such a shame a quality speaker and nice housing can be deemed useless by $3 worth of electronics.
I build guitar amps and the caps and resistors in those are just getting broken in after a decade of use. Even the electrolytics are good for 20-30 years if you play them a few times a year.
I can't argue with you. Perhaps you can connect one of your amp heads directly to the woofer and get a few more years use out of it. You'll just have to be careful not to overload the guitar amp input with the line level audio signal from your receiver (typically 500mV P=P). Good luck!
Hi Dennis
Can you fix my Polk audio psw 660 amp not working. My email is jadelmar@aol.com
dennisbsutube hi Dennis can you fix my Polk audio psw 660 amp stop working email me if I can send you the the rear panel. jadelmar@aol.com thank in advance Donald Delmar cell 847 814 4884
I appreciate your confidence, but I have been retired from the repair business for 25 years (a prior career). A good bench tech should be able to help you after he watches this video. Many models have similar circuitry. Good luck.
Hi Donnie, thank you for this video. Hi, I have a strange problem. I have connected single rca cable from my avr to the right input on the sub. However, when I pause the movie & play it back, it stops working. If I switch to left input then it starts working again. Can you please tell me what are the probable causes?
Ravi,
The unit does have an audio detection circuit that powers on the amp from a standby mode. I'm pretty sure most of this detection circuit is located near the input area of the main amp board. The small transistor that I replaced near the end of the video was part of this circuit. The small electrolytic caps and any switching transistor involved in this circuit are most likely the culprit.
I have just started electronics repair. I've been building computers since the 80's, so I am familiar with all of the components. However, I do not yet have the diagnostic skills I need. I found your video because I have the exact same sub with the same problem! How fortunate to have found you. I see some of your old school equipment and know right away that you know what you are talking about. I hope to learn as much as I can from you. My next project is an old ATX motherboard with 20 bad caps! I've gotten good at replacing them and have already fixed an Xbox. I see a pattern that around 90% of electronics failure is simply swollen/leaking capacitors. Would you agree with this?
When dealing with older electronics, electrolytic caps can be a common problem. When trouble-shooting newer equipment, semi-conductors such as voltage regulators, IC's, rectifiers, and transistors are more likely to fail versus caps.
@@dennisbsutube I noticed on my newer motherboards they use all-metal caps. They don't swell or leak, correct? So, then you can't visually see which ones need replaced?
@@CarsandCats They are actually made with aluminum cans. Even they will "dome-over" if they need to release pressure. That is why you will sometimes see a serrated top to allow it to bend up, not break.
Do capacitors go bad from NOT being used? I ask this question because I have had three working computer's burst caps after sitting for a few years. All of them were working perfectly before. In other words, should electronics be used once in a while just to keep them alive?
There are a lot of opinions on this topic. I think the most important thing is the manufacturing quality of the cap to begin with. Stick with buying known brand names from a respected national distributor. Also, store your electronics in a decent environment, not a hot attic or damp basement.
wow.. the best
Thanks!
Been struggling with opening board holes to insert new capacitors so read where using a stainless-steel dental pick and an iron works well. Just ordered some picks. Do you have a better way?
Yes. As I mentioned in the video, when dealing with a plated through-hole, add some fresh solder to the joint before trying to remove the old solder. This wll make the solder more liquid based when heating the joint and allow a "solder sucker" to quickly pull the solder from the joint.
@@dennisbsutube Can you recommend a solder sucker? My bulb one does nothing. It's very frustrating.
The original Soldapullit made in California.
eBay www.ebay.com/itm/272727193003?epid=28042051685&hash=item3f7fceb5ab:g:hnYAAOSwRsJeMuS5&amdata=enc%3AAQAHAAAAoNW4I58Dz34yoRzYrzMcJKOoE23WGxjFPK8QhiAc2UOs58vMcVcwOjtS8pRzFDdkJIQuxPHVKnurqQnyHlhp%2BGVEnDo5LaLR0vIxZ4GjQna9KPL0h9a9lwaWqcoimWCXMmEKUWGFfisD7c6XtbEf4a5W8ZgDDynafoiBZ95YIc23L%2FPefLFLdC4NkjgsNMAPwRPr9de64yegolMKsBpFNVs%3D%7Ctkp%3ABk9SR9br27iuYQ
Amazon: www.amazon.com/EDSYN-The-Original-Deluxe-SOLDAPULLT/dp/B006GOKVKI/ref=sr_1_5?crid=13PK2RDC90ZFB&keywords=soldapullt+solder+sucker&qid=1672680718&sprefix=soldapullit%2Caps%2C103&sr=8-5
Make sure you keep the rubber o-ring and tip lubricated with white lithium type grease.
I have one of these amps. It's currently working but past few nights I noticed some strange noises coming from it! It did it again today, I went to check it out and it was super hot. My other sub which is a different brand was on for the same amount of time, and it was not hot at all. I never paid attention on this amp if it normally gets hot after an hour or so of use. But something is going bad that's for sure. What I did notice was the large heat sick the one right next to the AC input It has voltage leaking onto it. When I touched it I could feel a slight shocking sensation. I measured it and the heat sink rail has 168vdc. No sure if that is normal on this thing or not. I would have thought it would be like a grounded part.... There are 3 transistors attached to it, and then some other electronic part that is white in color is strapped to it. Anyone know if this is normal on this power supply? I'm going to have to check all the capacitors because sounds like a lot go bad on this power supply.
Dexter,
The strange noises are a good indication some of the caps are going bad. Also, check the solder joints on the larger power resistors.
There should be no measurable current on the heat sink. Disconnect everything from the subwoofer except the power cord, then measure to make sure the problem is not coming from another source. It does sound like you have a short or a breakdown in a semi-conductor insulator on the heat sink. This can be a dangerous condition. I would contact Polk customer support and ask for an amp replacement due to their liability exposure to injury in this situation.
Are u willing to fix another one of these amps??
Sorry, I retired from the repair business quite a while ago. I no longer have a business license or the needed insurance to do any work for the public. I'm sure if you took your sub-woofer to an electronics repair shop and have them watch this video they will be able to help you. Thanks for watching!
Man, you need a business, I would totally send you things for repair!
Ha! I appreciate your comment but after spending 25 years in consumer electronics repair, and the next 25 years in video surveillance manufacturing, I'm ready to go fishing!
Wow...that makes u a happy 70 yr old treasure trove of troubleshooting resource that is going to recede into oblivion. Seriously, u need to continue making videos to educate. Especially loved the tip abt the refridgerant. A lost art revived!
Thanks! There are a lot of "board jockeys" out there these days. I'd like to make more trouble shooting videos when I get the opportunity. I have a Bang & Olufsen Beomaster 8000 receiver waiting on me!
Any amp issues can be quickly fixed by going to Parts Express. Com and purchasing a higher quality amp. I did this with my Polk PSW110 and it made a huge difference in sound quality from the OEM. I also have the PSW 505 save I'll be replacing the amp on this one soon as well.
Do you have any video of the amp replacement project?
@@happy_trails No, I don't. But it's not complicated. Just take out the screws and pull out the amp. There will be a putty type of sealant around the edge of the hole that'll give you a little resistance. Once the amp is removed, unplug the two wires from the speaker. Remember which prong the red and black wires were attached to because you'll have to make sure the new amp's wires are attached to the same prongs. You may need to cut a bigger hole for the new amp. Make sure to reapply new sealant around the edges of the hole, slide in the new amp and screw it down. That's it.
@@crinklestein2000 Which plate amp did you buy as a replacement?
What is the repair cost for this? I've seen people buy a sub $200 amp to replace it on Amazon with good success.
My main concern would be that it will continue to break down. My sub lasted nearly four years.
Coincidentally, I built my own sub with some MDF, an Amazon amp, and a Walmart woofer and it is still alive and strong after 9.5 years (though occasionally it will need to be unplugged and plugged back in because it quits working).
I like the sound of this sub, but I'm not convinced it's worth fixing the amp, vs buying a new amp.
Unfortunately there is no guaranteed answer to your dilemma. The parts list that I showed in the video only totaled around $15 as I recall. I checked with the owner of the unit and it is still working fine. Who knows if it will last 10 more days or 10 more years. It's worth a try if you have the time to spend on the project. Good luck!
This was informative. But you didn't earn my thumb up until you played queen.
Dude, polarity doesn't matter when testing caps with ESR meter.
Rip I just bought 2 of these used. Now I’m scared they’ll self destruct on me
I have three, two of the three have died with very light use, good luck..
That ESR meter is referencing a 25V cap when telling you what capacity the reading would be sufficient for.
Edit: you mentioned it later in the video. I probably ought to delete my comment. Maybe
I opened my amp up and it was full of some white goo which covered most of the capacitors. So I can't see the resistor numbers on the board.
The white goo is typically glue that is used to help hold parts in place during assembly. You can carefully scrape the glue off to see the value or condition of a part without hurting anything. FYI... resistors rarely go bad as compared to caps and semiconductors.
@@dennisbsutube I meant to say capacitors. I bought 10 of them to make to make the common repair, but that goo is difficult to pull off.
Can you repair my amp from the psw505?
I appreciate your confidence, but I have been retired from the repair business for 25 years (a prior career). A good bench tech should be able to help you after he watches this video. Knowing what the voltages should be coming out of the power supply will be a great help to the tech. Good luck!
hi..where are you located..need my sub fix??
Sorry, I retired from the repair business quite a while ago. I no longer have a business license or the needed insurance to do any work for the public. I'm sure if you took your sub-woofer to an electronics repair shop and have them watch this video they will be able to help you. Thanks for watching!
Hi can I get service manual plz
Polk does not have a service manual, schematic, or even a block diagram available for their sub woofers. They do a horrible job of supporting their products with their end customers.
Great repair video. Now I just need to find a tech skilled and willing enough to do it, because this is WAY past my pay grade.🤦♂️
Ha... Thanks! Good luck with your search.
I just had got one but I try to connect speakers to it and it won’t connect it will not play
1) Does the LED on the subwoofer stay RED, or does it turn GREEN?
2) Do the speakers work when connected directly to your stereo receiver or amp?
@@dennisbsutube mines just stays red and whenever it foes turn green it will only play got a little before then shutting off.
@@dennisbsutube I would really appreciate it if you could be any type if help. Ill even go as far as sending it out and paying you to fix it.
Mine failed in exactly the same way.
Can I send you my Polk psw505 am for repair
Stephen, sorry for the late reply. I have been out of town and my phone would not navigate to the comments section.
I appreciate your comments. Getting back into the repair business would require creating an entity, liability insurance, tax returns, etc. No thanks. I happy to share my knowledge. Find an electronics shop in your area and have them watch the video. I bet they will be able to fix your sub once they know what supply voltages to look for.
I have another PSW505 issue. Instead of +-57V it shows -0V and +14V.
Without any power connected to the unit (no AC), I would disconnect the power supply from the amp and do component level trouble-shooting looking for a load problem in the amp, or most likely some semiconductors that are open or shorted in the power supply.
@@dennisbsutube I disconnected the amp from power supply and checked U. It always +14V and -0V. Wondering why they are not symmetrical. I also verified capacitors and diodes in power supply.
@@postkvn1 Did you ever find a fix?
@@ehss192 I was able to fix power supply. Just changed one capacitor which is connected to IC 3843. Now I see +-57V. But there is another issue with amplifier.
@@postkvn1 Thanks for the tip! My amp died after 5 years and I'm digging into this myself now. Thanks for the reply.
You wouldn’t happen to live in NY do you? Lmao I need one rebuild.
I have 3 of these, 2 of the 3 have died, I'm expecting the third to die anytime now.. all three have had very light use
These have a very high failure rate, you could have a nice side hustle if you decided to do a board swap program
Thanks, but I'm trying to catch up on the domestic projects that I have been ignoring for too long. Perhaps Mr.Miles from the comment below would be interested in such a challenge.
@@dennisbsutube I need this repair for my 505. Can you do it?
@@kathywilliams7947 Sorry, I retired from the repair business some time ago and no longer have the insurance and current license to run a company. I'm sure if you have a tech from a local repair shop watch this video he/she will be able to help you.
Just knowing what the output voltages from the power supply should be is a great help to any tech.
*SO, WHAT AM I DOING WRONG???!!!* 🤔 I unscrewed the 10 screws around the parameter, however, my board didn't come out.
Sorry you are having a problem. If you are working on a PSW505 there are no other screws that I can remember other than the ones around the edge of the panel that need to be removed. Perhaps the plate is just sticking to the cabinet and needs to be popped loose with a sharp metal edge such as a putty knife.
@@dennisbsutube - Okay, I'll try that, but what about the other 13 smaller screws more on the interior of the back panel? Would those be causing the panel to stick? However, I noticed in your video that they're still on the rear panel even after you removed it.
@@dennisbsutube - Also, yes, mine is a PSW505 and makes that exact same horrible sound.
The smaller screws inside the perimeter hold the power supply, amp, and pre-amp boards to the back panel.
@@dennisbsutube - Okay, I got the back panel off with a paint scraper, however, Polk wants me to test the driver. However, my wires (unlike yours in the video) are on a very short leash and I can barely remove the panel out of the way to get to the driver. Also, I called Polk customer service, and all the girl could do is to tell me that she could send me instructions, even though, I told her that I already had instructions. 😫
But I don't know if this would make an difference, but here are the instructions that Polk emailed me, even though, I can't get to the driver. So, is there a trick to it?
There is a simple test to figure out if the amplifier or the driver is the issue.
1. Unplug the power cable from the subwoofer.
2. Remove the grille from the subwoofer.
3. Take out the screws that hold in the driver of the subwoofer (some models will have a foam ring covering the screws, just peel this away).
4. Once removed, there will be two wires connected to the driver, positive and negative. Pinch and pull the connectors off.
5. Take speaker wire from your receiver and directly hook it up to your driver.
6. Keeping it at a lower volume, play audio and see if the driver functions. It is not going to sound great being outside of the box, but we are testing for functionality.
If the driver works, the amplifier is the issue. If the driver does not work, the driver is the issue. Kindly reply back to this email once done with the test so we will know which part needs to be replaced.
I’ve never really heard good things about anything Polk audio, I could be wrong but I think they’re pretty shit
Do not buy these this is junk I was recommended by a receiver not this is junk I am FM receivers hundred times better it doesn't go out!!!