Pain in the ass to work on, no PIAs just gates and the schematics aren't quiet right. Little repair information out there.
Good luck trying to find a reputable repairer who is prepared to work on it.
I've been working on one as a favor between jobs for 2 months now. I will not work on another. If you don't know what you are doing don't touch the boards, the tracks are easily broken. I've spent so much time undoing all the previous repair attempts.