Well, I could choose between 3 Ms.Pac (and 2 or 3 Pac, but I definitely wanted Ms.) cabs. Seller explained two of them were completely dead but one showed the game screen but had "all kind of stripes" across the screen. So he offered to power them up one at a time and the one he mentioned fired up and WORKED

The screen did have some strange colors, but the attract ran fine AND I could credit it and start a game.
Regretfully it has a speed-up/different maze hack, but that can be reversed. The seller was about as surprised as I was to see is work right away. I'm very glad we already negotiated a price _before_ I went over because I bet he would have wanted more for a working game....

The two other cabs probably looked a bit better than mine, but I still went for the running machine of course, a running Ms.Pac board is pretty valuable as we all know.....and all cabs would need a full restore anyway.....well at least somewhere in the future....
Anyway, the problem he described sounded like bad sync on the monitor so I already had some hope it would just be adjusting a pot on the monitor.