Omega Race troubleshooting

When Omega Race was first plugged in, it appeared to be completely dead. Checking the monitor revealed that F100 and F101 were blown. Replaced those and the game came up. The screen appeared messed up but looked playable. It would coin up but no sounds. Replaced the Z-80 on the sound PCB and all sounds were working. Now it's time to troubleshoot the messed up screen issues. Looking at the screen you can see that all vectors on the X-axis are OK, but many of the Y-axis vectors are a mess. So far the following has been done- verified EPROMs, replaced LS 245, 04, and 32 near where the battery was, and swapped out all RAMS. Next I'll move on to using the HP10529a comparitor, checking the IC's in the vertical position circuitry.