Mr. & Mrs. Pac-Man
Bally, 1982You're currently viewing posts by Pinsider Richard_BoK.
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I would also check the 74... IC's. These are also used for selecting a ROM. (U14 / 17 / 18 / 19)
On the schematic they are drawn between the data / address bus and the rams/roms.
When they fail it can be measured with a DMM or probetester.
When pulses are on the input and the output is steady 0 or 5V something is wrong.
These kinda problems also cause the led to stay on.
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