Don't bother checking the -12V supply of the CD32, it does not have one!
From what I remember it used single rail Op-amps.
I would suggest cleaning the cd-lens in case that causes a problem and spray some contact cleaner on the volume control.
The capacitors referred to were those across the +5V supply, the PCB silkscreen is wrong. If your CD32 was manufactured after October 1993, it should be fine.
