Change the electrolytics around the 1.2 VDC switching regulator for the DSP (see service manual).
I used two parallel capacitors for each capacitor I replaced. The capacitors need to be low-ESR. Paralleling them even halves the ESR. If you use wired capacitors, you are able to do some thermal de-coupling while leaving the solder pads exposed to add a 100nf X7R capacitor parallel to the electrolytics.
I repaired a few of these units. Main symptoms are weird sound out of the speakers or no audio at all. Except in "PURE DIRECT" mode where the DSP is not involved.