Midway Games

[channelmaniac]

Model: Ms Pac Man
Symptom: Dead

Board had attempted repair damage.

Replaced the 4 factory PROMs with broken pins with 4 programmed EPROMs. Replaced 8 bad 2114 DRAMs and their sockets. Tested.

[channelmaniac]

Model: Pac Man Plus
Symptom: Dead

Board had attempted repair damage.

Repaired gouged trace. The CPU module was bad. Installed a Z80 CPU, 4 program EPROMs, 2 character EPROMs, Color PROM, Video Output PROM, and a Ms Pac Man daughter board to convert game to Ms Pac Man at customer's request.

[channelmaniac]

Model: NBA Hangtime
Symptom: RAM Errors

Board had physical damage. Straightened bent pins on U32 and removed 2 solder smears from the bottom of the board to fix RAM errors. Reprogrammed U112 to fix a ROM error. Tested.

[channelmaniac]

Model: Ultimate Mortal Kombat 3
Symptom: RAM Errors

Board had physical damage.

Replaced a bent pin on the PLCC socket for U45. Tested board. Reprogrammed U3, U113, and U132 to fix ROM errors. Tested board.

[channelmaniac]

Model: Galaga
Symptom: Parts board rebuild

Board had been worked on before and put into a box of parts boards by another tech. Two of the customs on the video board were in wrong sockets, one ROM was in the wrong socket, and the 06XX and 16K SRAM chips were missing.

Installed renew kit - all new sockets & resistor packs. Cleaned custom chip legs. Installed missing ICs. Repaired pins on the 02XX and the 07XX chips on the video board. Board would boot but would fail randomly on start up on different RAM chips. Replaced a bad 74LS138 at 1E on the video board to fix a random memory error on boot. Tested board.

[channelmaniac]

Model: Galaga
Symptom: Parts board rebuild

Board had been worked on before and put into a box of parts boards by another tech. Four resistor packs were replaced with the wrong type and a 5th had been replaced with the bad, flat style of resistor pack that should not be used on these boards.

Installed renew kit - all new sockets & replaced all old style resistor packs. Cleaned custom chip legs. Repaired pins on 2x 08XX, 51XX, and the 54XX chips on the CPU board. Board would boot but would fail with a 4L RAM error. Replaced a bad 08XX IC on the CPU board and tested.

[channelmaniac]

Model: Galaga
Symptom: Parts board rebuild

Board had been worked on before and put into a box of parts boards by another tech. Three caps had been replaced incorrectly.

Installed renew kit - all new sockets & replaced all old style resistor packs. Cleaned custom chip legs. Repaired 2 pins on one 08XX IC and replaced 3 incorrect caps - 2 radial and 1 axial that was physically too big. Removed tape from the edge connector and cleaned the residue. Tested board

[channelmaniac]

Model: Mortal Kombat 4, Revision 2
Symptom: Burnt components next to JAMMA edge conector

Replaced a bad 0 ohm surface mount resistor in the Video Ground circuit. Replaced a bad surface mount cap in the Sync Output and Blue Output circuits. Replaced a bad 33 ohm resistor in the Blue Output circuit. Board powered up but had no sync. Replaced a bad surface mount 7407 IC in the Sync Output circuit and tested the board.

[channelmaniac]

Model: Mortal Kombat III
Symptom: Dead

Jumpered 1 burnt trace where a coil used to be. Replaced a surface mount coil at L54 in the power circuit for a 74ABT244. Reflowed the DMA Controller at U33 and the Orbit chip at U32. Board booted with WWF instead of MKIII. Replaced all ROMs and the security chip. Tested. Board had graphics corruption. Replaced chip at U45 and retested.

[channelmaniac]

Model: MKII
Symptom: Reboots at random

Reflowed the surface mount DMA Controller IC. Tested.

[channelmaniac]

Model: WWF Wrestlemania
Symptom: Random reboots and garbage on screen

Reflowed the DMA Controller IC and fixed bent pins on a custom PLCC. Replaced bad U125. Cleaned battery contacts and tested.

[channelmaniac]

Model: UMK3
Symptom: Lines under players. Fails self tests showing all Graphics ROMs bad.

Resoldered the CPU and 3 RAMs to fix lines under player issue. Address lines A0-A6 on the Graphics ROMs were not being actrivated during self test. Replaced a bad 74F373 and tested.

[channelmaniac]

Model: Mortal Kombat 4
Symptom: No video sync

Replaced a dead SMT 74LS07 and a fried zero ohm SMT resistor in the video ground circuit. Tested.

[channelmaniac]

Model: Mortal Kombat 4
Symptom: No video output

Replaced 3 fried 33 ohm SMT resistors to fix the video output. Replaced a dead SMT 74LS07, a 1K SMT resistor, and a fried zero ohm SMT resistor in the video ground circuit to fix the sync issue. Tested.

[channelmaniac]

Model: NBA Max Hangtime
Symptom: Missing U36. No sound in game. 10 bongs during self test.

Replaced missing U36. Board would then boot but showed a ROM error. Reprogrammed U132 ROM. Board would boot but fail sound tests with 10 bongs. Replaced cracked SMT coil in the sound circuit. Tested.

[channelmaniac]

Model: WWF Wrestlemania
Symptom: Bad U14 during self tests

Replaced IC U14. Tested.

[channelmaniac]

Model: Ms Pac Man
Symptom: Dead

Cleaned the tarnished legs on 3 mask ROMs and corroded legs on 1 EPROM. Tested

[channelmaniac]

Model: Ms Pac Man
Symptom: Dead. Missing ribbon cable.

Board was part of a bulk buy and had a bootleg Ms Pac daughter board and no ROMs on row 6. Board was also poorly converted to run on DC power.

Removed several jumper wires and repaired a burnt pin on the edge connector. Installed ribbon cable and tested. Fixed broken pin on the sync buss controller chip. Board would still not boot. Replaced bad CPU and successfully tested.

Installed ROMs on row 6 and replaced the bootleg daughter board with an original. Since the bootleg board required no ROMs on row 6, kept that board as a troubleshooting tool for fixing Pac/Ms Pac/Pac Plus boardsets to quickly rule out ROM issues.

[channelmaniac]

Model: Ms Pac Man
Symptom: Dead

Board would boot if tapped "just right". Replaced sockets on the 74LS259 at 8K, the CPU, and the Z80 Sync Buss Controller. Board booted and worked, but had very thin horizontal lines bridging some text. Replaced the PROM at 4A and tested.

Replaced a bad 2200uf cap and an incorrect 330uf cap where someone used a radial instead of axial. Tested.

[channelmaniac]

Model: Pac Man
Symptom: Dead

Fixed bent pin 20 on CPU, replaced bad socket on Z80 Sync Buss Controller, and patched one bad trace. Tested.

[channelmaniac]

Model: Pac Man
Symptom: Dead

Replaced bad socket on Z80 Sync Buss Controller and replaced the Ms Pac ROMs on row 5 with Pac Man ROMs. Tested.

[channelmaniac]

Model: Ms Pac Man
Symptom: Dead

Replaced bad socket on ROM at 6E and the socket for the Z80 Sync Buss Controller. Replaced missing socket on the pins of the Z80 Sync Buss Controller card. Board would boot but had glitches in background graphics and missing characters. Replaced bad socket on the ROM at 5F to fix glitching and replaced a bad 74LS20 at 3E to fix the missing characters. Tested.

[channelmaniac]

Model: Pac Man
Symptom: Dead

Replaced bad CPU, ROM 6E, and fixed a broken pin on the EPROM in 6J. Jumpered a cut trace on 8C pin 11 to undo a mod someone had performed on the board. Replaced bad Mask ROMs at 5E and 5F. Board played but had horizontal lines across screen. Replaced bad RAM at 1C and tested. Repaired burnt edge connector and restested.

[channelmaniac]

Model: Pac Man
Symptom: Dead

CPU was dead. Checked /RESET and it was missing. Replaced bad 74LS161 at 9C. Board would try to boot but fail and the data bus would lock. Replaced bad 74LS245 at 4H. Tested.

[channelmaniac]

Model: Galaga
Symptom: Dead

Board had attempted repair damage. Board was part of a pile of parts boards to be resurrected and had already had the 40, 42, and 28 pin sockets replaced on the CPU board.

Cleaned the excess solder from the edge connector. The audio amp chip had severe heat damage. Replaced 4 incorrect radial capacitors with proper axial types. Removed solder short from the only correct axial type installed (C20) that grounded out the output of the audio amp chip. Removed the heat damaged audio amp chip, rebuilt missing ground trace with copper foil tape, installed replacement amp, and jumpered 2 missing signal traces to it.

Removed solder shorts from the 06xx and one of the 08xx chips. Boardset was still dead. Examined the custom ICs on the CPU board and discovered the 06xx was missing the ground pin. Replaced the damaged socket on the 06xx and attached a pin from a donor chip. Tested. Boardset still had no video but would now play blind.

Examined the video board. The 05XX chip had 5 broken pins. Replaced the old style resistor packs on the video board and replaced all the 24/28 pin sockets. Cleaned the legs on the customs. Replaced a wire patch on the 07XX chip with a leg from a donor chip. Repaired the 5 damaged pins on the 05XX custom chip with legs off a donor chip. Tested board.

NOTE: The PROM at 5N outputs the video. The enable line (pin 15) for it is controlled by the 05XX. The missing power pin caused the 05XX to be dead and not enable video output.