I fixed several compact and classic Macintosh computers about a year to six months ago, if you run the boards through the dishwasher and replace all the electrolytic capacitors, they work great. I have a Classic with a Classic II logic board that had a similar issue, that fixed it right up. Also replaced all the caps on the analog board and the system fan for good measure.

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[This message has been edited by RWDPLZ (edited 07-15-2018).]