Is there any diagram available for this unit? Even partial could be helpful.
I found several electrolytic caps leaking and the majority had high ESR. I replaced the whole lot excluding two large ones.
Now self test passes. Short and open compensation works fine too. I can measure resistors with good accuracy but known good capacitors measure about 20% lower with ESR of several ohms so the unit still has some problems. I noticed one of the daughter boards which hosts two flat-pack transistors is overheating. Especially several SMD resistors get really hot.
Any help appreciated