IIsi weak sound volume, can anyone here narrow down the caps needing replacement?

[DaiyuHurst]

Hi folks,
I have one complete IIsi and another with a dead PSU, but both exhibiting very weak sound output
(of course, I have to swap in the good PSU for the one). Can anyone here narrow down which caps need replacing?

Dai

 

[finkmac]

have you replaced any of the mainboard caps?

is the "good" power supply recapped?

 

[DaiyuHurst]

have you replaced any of the mainboard caps?

is the "good" power supply recapped?

I doubt any of these bits have had any love - they were eBay purchases. At least they didn't experience battery rot.

I have a third board that's dead as a doornail.

 

[Callan]

All of the electrolytic caps need to be replaced. They're all leaking already. Bet on it. If you haven't capped your power supply you best do that too.
As for your weak sound. Make sure to check your speaker and the leaf springs that connect the speaker to the motherboard (clean them / check tension). Motherboard side - check uk3 and transistors 1a & 2a.