Midway Games

[channelmaniac]

Model: Galaga
Symptom: Dead. Garbage on screen

Replaced all 24/28/40/42 pin sockets on the CPU and video boards. Replaced all the old style resistor packs on the video board. Installed new interconnect cable and replaced a bad 74LS245 on the video board. Repaired 2 broken traces on the video board. Tested. Recapped the audio section and replaced the 2 470uf power filter caps. Retested.

[channelmaniac]

Model: Galaga
Symptom: Missing player/text graphics

Fixed 3 broken pins on the 54xx, 1 ea. on 2 of the 8xx chips. 1 trace on the 51xx chip where the socket was replaced by 2 old single wipe cut down sockets. The CPU sockets were dual wipe and OK. Replaced the 28 and 42 pin sockets and all the old style resistor packs. It booted with a ROM 03 error. Pulled the ROM at 3L out of the socket and fixed a bent pin. Replaced the 24 pin sockets to finish the CPU board.

Replaced the 24/28 pin sockets and the old style resistor packs on the video board. Fixed a broken pin on the 00xx and 05xx chips. Fixed a bad trace on the 1K resistor pack. Tested the boardset and found the sound for the player ship being captured by the enemy was incorrect. Replaced mismatched sound ROM at 3E and retested.

[channelmaniac]

Model: Pac Man
Symptom: Graphic Corruption

Socket on 5F was previously replaced.

Found 3 damaged traces on 5F. Jumpered traces and tested. Graphics were better but still slightly corrupt. Removed socket from 5F, removed damaged trace causing short, and reinstalled socket. Tested. Sound was corrupt. Replaced bad 74LS86 at 4F and retested.

[channelmaniac]

Model: Pac Man
Symptom: Dead

Fixed 3 broken solder joints on the Sync Buss Controller board. Game would boot the Six Pac mod, but had graphic corruption. Replaced bad CPU and retested. The upper address lines were not working correctly and bank switching was failing.

[channelmaniac]

Model: Mortal Kombat
Symptom: Low audio

Cleaned under a leaky 220uf cap on the audio board, recapped the audio board, and tested.

[channelmaniac]

Model: Mortal Kombat
Symptom: Crackling and low audio

Cleaned under the leaking 100uf and 220uf caps on the audio board, recapped the audio board, and tested.

[channelmaniac]

Model: Mortal Kombat
Symptom: Low audio until board warms up

Cleaned under the leaking 220uf cap on the audio board, recapped the audio board, and tested.

[channelmaniac]

Model: Mortal Kombat
Symptom: Low and crackling audio

Cleaned under 3 220uf, 1 2200uf, and 5 100uf caps that were leaking on the audio board. Recapped the audio board and tested.

[channelmaniac]

Model: Pac Man
Symptom: Burnt edge connector

Repaired the edge connector with copper tape and tested.

[channelmaniac]

Model: Ms Pac Man
Symptom: Burnt edge connector

Repaired edge connector with copper trace tape. Tested.

[channelmaniac]

Model: Ms. Pac Man
Symptom: Dead

Replaced missing Z80 Sync Buss Controller module and the 28 pin socket in mounts to. Replaced a bad 74LS283 in the sound circuit. Tested.

[channelmaniac]

Model: Carnevil
Symptom: No sync.

Replaced bad 7407 IC and tested.

[channelmaniac]

Model: Rampage World Tour
Symptom: Random errors that change with board flexing

Reflowed U1, U13, U24, U25, U32, U33, U36, U37, U38, U39, U65, and U66. Tested.

[channelmaniac]

Model: NBA Hangtime
Symptom: Bad background noise in audio

Replaced bad TL092 OpAmp at U92. Tested.

[channelmaniac]

Model: Galaga
Symptom: Freezes, randomly coins up by itself.

Board has had repair attempts before. All the 2147 RAMs were pulled and 2x 2148 RAMs installed by another tech.

Replaced all the 24, 28, 40, and 42 pin sockets. Replaced all the old style resistor packs. Found a 2.2K pack that had a broken pin causing the freezes and a 5 pin 1K pack with 2 broken pins causing color issues that the previous tech replaced the RAM for. Recapped the board. Repaired bad pin on the 52xx causing the coinup issues. Repaired a bad pin on the 04XX chip. Tested.

[channelmaniac]

Model: Galaga
Symptom: Freezes and resets on its own

Board had been worked on in the past by another tech.

Replaced the 24, 28, and 40 pin sockets on the CPU board. The resistor packs were of the proper type and the remaining sockets were machine pin and did not need replacing. Found all of the 24 pin sockets on the EPROMs were incorrectly installed, standing off the board about 1/16", and two of them had pins that had broken off under the socket causing the bad behavior. Tested board.

[channelmaniac]

Model: Rampage World Tour
Symptom: Graphical Corruption during game

Board had stripes and bleeding colors throughout playfield and outside of the playfield around the screen borders.

Replaced U32, U10, U11, U14, U15, U38, and U75. Tested.

[channelmaniac]

Model: Mortal Kombat 4
Symptom: No sync, burned component.

Rebuilt burnt traces and pads, replaced a burnt 0 ohm resistor in the video ground circuit, and replaced a missing surface mount capacitor. Tested board. Replaced bad surface mount 7407 IC to fix missing sync. Retested to find sync fixed but some buttons not working. Cleaned JAMMA edge connector and tested board again.