Hyper Sports Repair Logs
Board would display garbage upon power up. Checked and cleaned the program ROM legs. Repaired a corroded leg on the C06 EPROM then replaced corroded socketson the C05 and C06 EPROMs. The board would then power up and play but had graphics corruption on text elements.
Cleaned the EPROM and custom chip legs on the video board to finish the repair.
Symptom: Dead. Graphics corruption. Foreground AND background.
This is a board from hell. Not sure what happened to it but it HAD to be a power surge of some kind.
Replaced the 74LS04 on the CPU board to fix the dead CPU issue. On the video board, EPROM C26 was bad. Replaced. Signals on the address lines of C11 to C18 were incorrect. Replaced F15 and F16
Working backwards from the video outputs I found: Output pins stuck on MOST LS157 ICs. Replaced C17, D17, E17, D16, and A4 Output pins stuck on D11, E11, E12, G12, E13, F13, G13, and F14. Pins racing on D9, E9, E10, H10, and J10.
All of those chips tested bad on my EPROM programmer.
Now I have graphics but have some sparklies around border graphics and a missing title screen to track down. Bad LS377 at H12 on the video board. Replaced and the board is now fixed.