Yeah, I just bought a pin that the seller said all the issues he knew about, was fairly thorough. Brought the game home and and the DMD went out the next day, board issue.
I have bought from this guy before and 100% don't expect him to fix it. I just take it as one of those risk when buying old electronics, you know?
Totally sorry about your situation, it's really frustrating. I am lucky enough to have an AWESOME tech in this area who is not overly costly and I just bring him over right away.