My Repair Log

[iankellogg]

I figured Since I have been working on a lot of games lately I should start posting my repair log.

[iankellogg]

Pole Position
Problem
Acquired game in completely non-working condition. Monitor has raster gray, board is unpowered.
Solution
Wiring harness was hacked up, replaced harness with new one. Did power mod to PCB and now board boots to blue screen of random garbage

Problem
Game is booting to blue screen and garbage, no sound.
Solution
2 namco custom chips on CPU board had missing legs. added in jumper wire to fix chips. Board now booting to RAM 06 error


Problem
Board boots to RAM 06 error
Solution
Replaced 7J and 7K on CPU board with new 2114 ram chips


Problem
Board boots to RAM 00 error
Solution
Replaced 8F on Video board with new 2114 Ram chips


Problem
Coin mechs and shifter is not working
Solution
replaced resistor array at 9N.

[iankellogg]

Scramble
Problem
Sprites are missing lines and colors
Solution
2716 EPROM at 5H had a broken leg, burned new chip works perfectly now.

[iankellogg]

Phoenix
Problem
Board shows no sign of life. no clock, no signals.
Solution
Both C2 and C1 were missing, replaced capacitors. Clock still not oscillating. IC7 74LS7404 low on all logic outputs. Replaced IC7. Clock oscillates, game plays.

[iankellogg]

Time Pilot Bootleg
Problem
Graphics are scrambled
Solution
Took all the parts off the board and trashed the board. fuck bootlegs

[pimppride]

I like that, keep a history of what you've done from day one...

on a side note : I always wondered why manufactures did not insist on a pouch inside the games back door from manufacture, that could hold the user manual & more importantly log sheets for history of tech repairs, dates ect...

to log the history of what was done to a cabinet...

I'm implementing this on my machines, this way I don't have to guess on what repairs I done years from now...

[iankellogg]

Cruising World
Problem
Monitor was dead, audible clicking sound coming from monitor
Solution
Solder bridge on CN15K. Still causing clicking. Dead Q101, no longer clicking but no visuals.
R510 was getting hot, Z500 was open both directions so replaced. Random color lines now visible, LM1203 now getting very hot.
Replaced LM1203, all fixed.

[John's Arcade]

Nice, Ian! Good idea. 

[iankellogg]

Ms Pac-Man
Problem
Ms Pac-Man shows no video when plugged in
Solution
Missing Z80 from daughter board. Removed Daughter board and put a new Z80 into the Z80 socket on main pcb to enable further testing.
TIP Ms Pac-man will run Pacman if you remove the daughter board and place a Z80 in the socket. This makes it easier to debug than dealing with the daughter card.

Problem
PCB shows video but is just garbage

Solution
All eproms were damaged, with missing legs, or bad checksums. Replaced all eproms.
7M was missing pin 7, removed 7M and noticed damaged pads and broken traces.


Replaced with socket and new 74LS139. Ran mod wires to fix broken traces.

Problem
PCB still shows garbage but it is now changing between garbage and colored squares, unable to take a photo due to rate of image change.
Solution
Noticed a very rusted 2114 Static ram chip at 4K. Removed chip and had half the pins fall off. Replaced socket and ram chip.

Problem
PCB now booting to a screen full of white zeros
Solution
Put the game into test mode, game reports 4L is bad, replaced 2114 sram. Board now booting and playable.

Changed 5E and 5F back to ms pac roms and put the daughter card back and now I have a working ms pac again.

[iankellogg]

Galaxian
Problem
Galaxian boots to show what looks like "bad ram 1" but the 1 and other chars are disappearing randomly

Solution
Originally I thought this meant a bad memory chip, according to the manual a game booting to BAD RAM 1 means a 2114 sram chip at 7N or 7P is bad. I pulled the two chips and put in new ones with no change. Put the old srams back and decided to give the eproms a once over.
Pulled each eprom off the daughterboard and ran it through romident. 7W didn't match but I have no more 2716s so I went for a backup plan.
Replaced daughter board with single 27128 eprom

This is temporary until new eproms come in the mail.

[iankellogg]

Space Invaders
Problem
Space invaders shows fat and thin lines onscreen but they are moving. normally when space invaders has no roms installed it will show fat and thin lines statically. The lines were moving regardless of what eprom was installed.

Solution
74153 at D2, C2, B2, and A2 apparently were bad. Traced data signals correctly to these chips but with incorrect data coming out of each of them. Control signals A and B on 74153 were correct. Logic pen suggested chips were fine but scope results showed that data output from 74153 was matching control signal A. Replaced each chip before board booted.

Sorry for lack of pictures on this one.

[iankellogg]

Mappy
Problem
Game would not boot. constant screeching sound out of speaker with RAM error on screen. Again sorry for lack of pictures, this was a rush job for someone.
Solution
Previous owner installed Z80 in sound processor socket, which should be a 6809. Replaced z80 with 6809.

[iankellogg]

Galaga
Problem
Game failed to boot, staying at a static garbage screen
Solution
Removed each namco custom and cleaned legs with a brillo pad.



Problem
Game would boot to attract mode and then reset immediately
Solution
This would only occur when the game was installed in the cabinet. I pulled the board out and connected it to the harness and then it started working. Appears the ribbon cable that connects the CPU and Video board is bad. Temporary fix was to bend the ribbon cable in such a way that it would work while installed. Will be replaced with brand new ribbon cable.