MikesArcade.com Coin-op Video Arcade Technical Information Archive
  Home  |  Repair Logs  |  Game Manuals  |  Monitor Manuals  |  Online Store  |  Links  |  Contact Us
Technical Info
  Repair Logs
  Pacman fixes
  Manuals & Schematics
  Monitor Manuals
  Nintendo Game List
  Nintendo Joysticks
  Nintendo Buttons
  Data I/O Promlink 6.10
Spies Wiretap Archives
  Coin-op Video Game List
  Game Conversions
  The Mixed Bag
  PCB Pinouts and DIPs
PDF Game Artwork
  Coin door inserts, etc.
  Instructions cards
  Operation Sheets
  Control Panel & Bezels
  Title Strip Creator
  Component markings...
  Crating a game
  Build your own cabinet
Board Upgrades
  Double Donkey Kong
  Items I'm looking for
  Contact Us
  Visual C Project files
  Valid HTML 4.01!

Pac-man board problems and fixes

Some of these Pac-man boards have Ms. Pac-man character roms, so ignore the strange looking Pac-man in the maze. As the fixes are determined, I will post them below the description for each image. Click on the images for a larger view. If you have any suggestions what the problems might be, please email us here.

We also now host the Greg King's Pac-man Troubleshooting page with pictures from ArcadeGameOver.com.

Screen shot Screen shot
Problem: Ghosts and Pac-man are composed of the same right half of the character, this only happens on Moving characters, the Pacs at the bottom of the screen and the Ghosts on the top of the intro screen are fine.
Fix: Stuck output on 74LS86 pin 6 at 2H. This is easily reproduced by shorting pin 6 and pin 7 together on this chip.

Screen shot
Problem: Entire screen is composed of A's, the Ghosts are part of Super Pac-man, game playes fine.
Fix: Replaced bad 74LS273 at 4D with stuck outputs.

Screen shot Screen shot
Problem: Strange lines troughout the images even when switch 8 is on.
Static appears also when the game is running (switch 8 off).
Fix:Replace the 74LS368 at 8E, pin 10 was rusted and falling off.

Screen shot Screen shot
No Moving characters on the title screen. No Moving characters during gameplay.
Dots visible & disappear as eaten.
Fix:Broken trace between 74LS20 @ 3E, pin 8 and 74LS174 @ 1H, pin 14.

Screen shot Screen shot
Problem: The board would cycle between the 2 screens. Staying on the 2nd about 3 or 4 seconds, then reset and display the 1st for an instant. Wash, rinse, repeat. :)
Fix: This was a compound problem. Both 284 and 285 sockets were bad causing the reboots and the rams at locations 4K & 4L were bad causing the garbage on the screen.

Screen shot
Problem: All motion graphics repeat horizontally.
Fix: Shorted trace to jumper pads on backside of board at location 1A, pins 3, 6 and 7.

Screen shot
Problem: Maze is consistently messed up in the same areas.
Fix: none yet

Screen shot Screen shot
Screen shot Screen shot
Problem: Mixed up graphics. Graphics repeat at odd places on the screen.
High score section is written in the left half of the screen vertically from the bottom up.
Fix: Broken traces to the 284 card. A8 was floating.

Screen shot Screen shot
Problem: I had Multiple board with the same problem. Pac-man and Ghosts split in two as they move across the center part of the screen. Also characters sometimes appear at 2 places at once.
Fix #1:Replace 74LS283 at 2F
Fix #2:Replace 74LS20 at 3E
Fix #3:Broken pin 5 on 74LS00 at 4C. I had 3 like this, they were Driving Force conversions at one time

Screen shot
Problem: Then entire playfield is filled with alternating colored horizontal lines
Fix: Bad 2125 rams.  Replaced them all at 2A,2B,2C,2D.  There was "goo" under them causing all kinds of shorts between legs.  After cleaning them off, only 2A was actually bad.

Screen shot
Problem: Two of same sprites on the screen at the same time. two pac-mans on screen
Fix: None yet

Screen shot
Problem: Red horizontal lines through the entire screen
Fix: Bad RAMS at 2B and 2D, both 2125s


Home  |  Online Store  |  Repair Logs  |  Manuals and Schematics  |  Monitor Manuals  |  Component Markings  |  Links

All Content Copyright © 2000-2024 by MikesArcade.com