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Polk_Hack wrote: »

Realizing that requesting PSW110 service manual is now basically a meme on this forum. I am going to humbly request one anyway and duck for the incoming ridicule. I am going to replace the filter cap that is on this board id# Q9092704627, Subwoofer DOM Jul-2009.

If the service doc has test point voltages, I will be lucky lucky, otherwise, just work through what should be a fairly simple troubleshooting. Mailbox is (omit symbols) MCL^345^ at the google gmail domain. Thanks in advance if you choose to help!

If you read my first posts on this forum, I was also looking for reference voltages, I couldn't figure out why the quiescent supply voltage was so low and I thought that was the problem. It took me a long time to figure out that it wasn't, so I'm trying to save your time:
The only voltage reference you have is the power supply of the op amps of the pre-amplification stage downstream of the stabilizers, but the power amplifier stage works in class H, the power supply is dynamic and varies based on the amplitude of the amplified signal.
In few wrods from Wikipedia: "Class-H amplifiers create an infinitely variable (analog) supply rail. They are sometimes referred to as rail trackers. This is done by modulating the supply rails so that the rails are only a few volts larger than the output signal "tracking" it at any given time"
Read also here: https://www.psaudio.com/blogs/pauls-posts/bashing-amps?srsltid=AfmBOop17pFuFmiDTrnt2mDJnIyG5I6IGiXR6dab7dpzPrgmsNWyJ3tf
If the problem is only the heartbeat, even if the cause is probably only the two capacitors upstream of the op amp power supply stabilizer, I recommend replacing all the power supply capacitors with long life, low esr, 105 C°, branded ones, I mainly used Panasonic FR or FC series, except the main filtering one (once the PCB was removed I also replaced that one even if there was no need). Be careful with the copper tracks, they are very delicate