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Garbled Pac-Man, Ghost and Fruit Sprites
Repair Case Summary
This page documents a firsthand Garbled Pac-Man, Ghost and Fruit Sprites repair case.
It is intended for technicians and collectors troubleshooting original Pac-Man or Ms. Pac-Man arcade PCB hardware.
Date: 2017-05-21
Board: Original Pac-Man PCB
Category: Sprite graphics
Symptoms:
Pac-Man and ghost sprites were garbled while the board otherwise functioned.
Pac-Man appeared divided into small quadrants with a small yellow dot/circle in each section.
Ghosts appeared as quadrant/block-like shapes containing numbers and colored items.
The on-screen fruit displayed a number instead of the proper graphic.
Diagnostic observations / tests:
After troubleshooting, the fault was narrowed to 74LS174 at 1H.
Components / locations investigated: 1H, 74LS174
Root cause: Bad 74LS174 at 1H.
Repair: Installed a socket and replacement 74LS174 at 1H.
This is a firsthand physical repair case. The same symptom on another Pac-Man or Ms. Pac-Man PCB can have a different electrical cause. Use the documented diagnostic observations and tests to guide troubleshooting rather than replacing a component solely because it repaired this board.