Midway Games

[channelmaniac]

Model: Offroad Challenge
Symptom: Dead

Replaced physically damaged DSP chip and tested. Still dead. Checked the 4 program EPROMs and the sound program ROM, all were erased in poor storage. Reprogrammed the ROMs and tested.

[channelmaniac]

Model: Space Invaders Deluxe
Symptom: Crashes and reboots

Replaced 1 bad RAM and 3 ICs in the reset circuit to fix a glitch there. Tested.

[channelmaniac]

Model: Pac Man
Symptom: Dead

Repaired burnt edge connector and broken DIP switches and tested. Board was stuck in a boot loop. Replaced bad RAM and board booted but had no sound and horizontal lines through graphics. Repaired broken leg on ROM on row 5 to fix the graphics issue. Replaced bad LM377 audio amplifier IC to finish the repair. Tested.

[channelmaniac]

Model: Ms Pac Man
Symptom: Dead

Board was missing ribbon cable.

Cleaned solder globs on the edge connector. Replaced missing ribbon cable. Tested.

[channelmaniac]

Model: NBA Hangtime
Symptom: Corrupt graphics

Enabled self tests to see U10, U130, U123, and U112 errors. Reflowed the lifted corner of the RAM at U10 to fix that issue. Reprogrammed U130, U123, and U112 to fix the U112 error. Replaced the sockets for U130 and U123 to fix those errors and the remaining graphics issues.  Tested.

[channelmaniac]

Model: Rally-X
Symptom: No sprites

Replaced the three cables between the PCB. Replaced a 74LS157 and 74LS04 in the sprite RAM circuit. Fixed a bent pin on a custom chip. Tested.

[channelmaniac]

Model: Space Invaders
Symptom: Missing sounds

Replaced bad 4006 and 4030 ICs to fix the missile and base explosion sounds. Replaced bad 7417 chip to fix the missing thump sounds. Replaced 1uf cap and 39K resistor in the UFO sound circuit. Tested.

[channelmaniac]

Model: Space Invaders
Symptom: Missing sounds

Replaced bad 556 time to fix missing thump and low saucer sound issues. The output was stuck high on the 556 causing the output from the SN76477 to be overridden. Tested.

[channelmaniac]

Model: Space Invaders Deluxe
Symptom: Dead. Corrosion damage

Replaced corrosion damaged CPU socket and cleaned the CPU legs. Replaced corrosion damaged H and G ROMs and their sockets. Patched a dead corrosion damaged trace on data line D6 between G and H. Tested with a diagnostic ROM: Bad RAM at 8, B, and H. Replaced and socketed the three RAMs. Tested. Missing several sounds. Cleaned daughterboard finger contacts to fix the missing thump sounds. Replaced 5 LM3900 chips to fix all the missing sound issues. Tested.

[channelmaniac]

Model: Rally-X
Symptom: Dead. Missing Resistor Pack

Installed missing resistor pack. Cleaned dirt from board interconnects to fix missing /RESET signal on CPU. Removed, repaired, and reinstalled bent and shorting volume pot. Replaced bad 741 Op Amp and recapped the audio section to fix thumping oscillation in audio output. Replaced bad .1uf capacitor to fix explosion sounds. Tested.

[channelmaniac]

Model: NBA Jam Tournament Edition
Symptom: Graphic corruption

Players were missing at tip off for game. Game would randomly reboot and get stuck in a shot clock violation loop during attract mode. Test screen displayed a corrupt basketball court image on the lower half of the screen.

Reflowed UE13 and replaced a bad socket on UF5 to fix the reboot and shot clock issues. UF5 was the wrong type for the game. It was for the NBA Jam game, not tournament edition. Replaced the Tournament Edition ROMs with regular NBA Jam ROMs and the remaining graphics issues went away.

[channelmaniac]

Model: Ms Pac Man
Symptom: Randomly reboots

Replaced Sync Bus Controller socket and ROM sockets. Replaced ROM at 6F as it failed reprogramming. Fixed solder smear on parts side and a pin shorting to a trace on a RAM chip. Replaced a bad 74LS138 in the address decoding circuit as it was putting out 3v on the R/W signal trace from an input pin. Tested for 5 hours without a reboot.

[channelmaniac]

Model: Ms Pac Man
Symptom: Dead

Replaced missing crystal and cleaned ROM legs. Replaced corroded sacrificial sockets on the Sync Bus Controller and VRAM Addresser and their sockets on the board. Replaced the corroded CPU socket. Board would boot and pass diagnostics ROM, but would not boot the game. Replaced bad 74LS74 at 8C holding the /IRQ pin low. Retested. Replaced bad ribbon cable and tested game with daughterboard successfully. Recapped PCB and tested.

[channelmaniac]

Model: Mortal Kombat
Symptom: Garbage on screen.

Garbage was in a recognizable pattern. Removed a corroded dual-port video RAM, checked the traces under it, and replaced it. Fixed a smeared solder short on the bottom of the PCB. Straightened the pins on the bottom side of the PCB for the video RAM and now had a clear picture but a U99 error. Straightened pins on the graphics ROMs to fix that error. Straightened the pins for the sound board connectors and the kick harness connector. Cleaned and recapped the sound PCB. Replaced an electrolyte corrosion damaged audio amp chip and a missing crystal. Tested.

[channelmaniac]

Model: Mortal Kombat II
Symptom: Test and repair board

Board had a burned +5v contact on the edge connector. Repaired. Replaced corroded P5 connector for the kick harness. Powered up game to find 2 bongs from the sound board. Replaced bad ROM U2 and corroded socket. Recapped the sound PCB as the radial caps were leaking on the PCB and the axial ones are known for drying out and causing scratchy noises. Tested. Board would sometimes jump straight to Game Over when start is pressed. Cleaned the grungy legs on the UG12/UJ12 Program ROMs, reseated the CPU and PLCC custom IC. Reflowed the custom DMA controller at UE13 and replaced its four filter caps. Tested.

[channelmaniac]

Model: NBA Jam TE
Symptom: Corrupt graphics

Straightened bent pins on the bottom of the PCB, replaced a bad 84 pin PLCC socket on a custom chip, and tested. Two ROMs showed as bad. Swapped the two incorrectly installed ROMs and retested successfully.

[channelmaniac]

Model: Total Carnage
Symptom: Crackly sound

Recapped sound PCB and tested.

[channelmaniac]

Model: Pac Man (modified)
Symptom: Dead

Board was missing the 2 daughter cards and was hacked with a single ROM and 2 switches to go between normal / fast and Pac / Ms Pac.

Installed missing daughterboards and tested. Board would try to boot and fail with a single 0 on the screen. Replaced bad Z80 CPU and tested.

[channelmaniac]

Model: Ms Pac man
Symptom: Damaged edge connector.

Removed all the crumpled up copper foil and cleaned the edge connector. Installed copper trace tape to patch the edge connector and tested. Replaced bad ROM at 5F. Tested. Replaced bad ribbon cable. Tested. Fixed broken solder joint on the Sync Bus Controller module to fix a crashing issue.  Replaced bad socket on the VRAM Addresser module and the socket for it on the PCB to fix video corruption. Replaced bad audio amplifier IC to fix missing audio. Tested.

[channelmaniac]

Model: Space Invaders
Symptom: Dead

Replaced shorted 10uf tantalum cap on the 12v line under the heatsink on the sound PCB. Tested - missing sounds except Saucer and background bass. Replaced 6 LM3900 chips and 2 560K resistors. Tested.