I removed the CPU board to re-locate the battery holder. After putting the CPU board back the playfield lost drive in the sense that no lights or solenoids except the flippers are working.
I can start a game, DMD works, sound works, the switches register and gives a score and the flippers work, but no lights are active, no ball kicks out and the slingshots and pop-bumbers don't fire (but the switches register and give a score).
My simple minded guess is that there's something wrong with the ribbon (data) cable connecting the CPU board and the driver board but I don't really have a clue what's wrong.
Does any of you know what might be wrong and where to start looking? Appreciate the help.