Konami Repairs

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channelmaniac:
Model: Simpsons
Symptom: Plays blind - random garbage on screen.

Board would sometimes work perfectly then on next power up be scrambled again. Resoldered damaged pins on 053247 at 7J and repaired 1 shorted trace where a solder pad was mashed into a neighboring trace. This helped but did not fix it. Replaced missing 051550 hybrid IC and tested. Board worked except was missing sounds 01 through 28. Found a factory solder bridge between pins 23 and 24 of 053260 at 3E. Removed the bridge and all the sounds are now working. Ran self tests and found the P4 down control stuck low. Replaced a bad 005273 hybrid module at S37 to fix. Played the game all the way through to check it out.

channelmaniac:
Model: Hyper Sports
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.

channelmaniac:
Model: Hyper Olympics 84
Symptom: Dead

CPU board tested good by substitution. Replaced bad 504 and 082 custom Konami chips. Board now runs but has corrupt player graphics. Signal DM7 (pin 11 of H3) is stuck low causing the corruption. The chip at H3 and the chips it drives at J4 and H4 are all good. The CLK4 signal is incorrect. A check of a good board shows pulses in groups of 3 and the bad board shows pulses in groups of 2... Replaced a bad 74LS20 at location E16 to finish the repair.

channelmaniac:
Tip: Konami custom chip replacements

Konami used some PC daughter boards to replace custom ICs.

PWB 402034 = Custom IC # 501
PWB 4000206A = Custom IC # 504

channelmaniac:
Model: Mystic Warrior
Symptom: RAM Failure

Self test showed that 9E, 10E, and 11E had failed. Inspected the board and found 3 bent/shorted pins on the custom IC 054338 at 10C. Fixed the pins and tested the board.

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