Here's something I haven't run across before. This driver board came into the shop with several others. According to the board's owner he got it as an extra board with a game he purchased. When I first tested it on my test fixture it would cause the MPU to lock up. No boot, just two solid LEDs on the MPU. After replacing the 40 pin connector and all three PIAs and their sockets it boots, but with a weird lamp matrix issue. It looks fine in lamp test (that's the first part of the video), but in attract mode it acts like whenever any lamp in a row is on, every other lamp in that row is on as well (second part of the video). I'm not sure that the fact that it appears normal in test mode is significant since the lamps test lights entire rows and not just single lamps in a row. I also replaced IC19 which controls most (but not all) of the lamp rows, no change. Switch matrix and solenoids work normally on the test fixture. I've tried switching the PIAs around, no help. The original PIAs as well as the three new ones all test good on my tester. Anyone have any ideas?

Solved it! The 7408 at IC13 was bad.