I had this XP80 for repairs, but I’m noticing that it is already repaired (some SMT capacitors have been replaced and a part of the board near the PCM69 DACs is scratched indicating that it has been corroded by electrolyte leaks.
The ServiceManual is quite poor in information, so for now I have only verified that the supply voltages are correct, but I have no information to verify the signals with the oscilloscope.
The defect is currently visible in the following video, while the button illumination lasts for a moment or not at all. By heating with a hairdryer, the button lighting lasts for a few seconds after turning it on and the display seems to struggle but returns to the condition visible in the video.
Has anyone ever had this problem? I was thinking of replacing all the SMT electrolytics, but I would have preferred to have some certainty that some circuits were not damaged…
Ah, Test Mode doesn’t work…
Thanks for any advice!
Gianluca
Hello again! I noticed that after a while of working in the board (a few days) the reset signal was missing at the pin6 of IC8 (M51953): the cause was the IC25 (74HC08). Replaced IC25 the reset is now present.
The supply rails are OK and they reach correctly the board: -12V, +12V, +D5V. By +12V is derived a +R5V with a 78L05, and it’s present too.
Now I’m stuck, the symptoms are the same as the video, and I don’t know where restrict the controls…
Any clue? Thank you very much!
Ah, the board is a 70567012, if anyone have it as a spare…
Fulcro