Ok so I'm pulling my hair out on this one, been working on a WPC89 power driver board for a friend for his T2, board has 50v, 20v, 18v, 12v unregulated, 12v regulated, 5v all OK... machine boots (I get sound, DMD and can go through the menus and such) but I get no outputs from the driver board, no GI, no lamps, no solenoids, it's almost like if the ribbon was unplugged completely (I've tried several known good ribbons) and I know the CPU board is outputting data because a known good power driver board works just fine in the same machine
I don't think every 74LS374 on the driver board could have gone bad at the same time? seems unlikely??
anyone encountered something like this before??