Galaxian Repair Log

Scott C

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Donor 3 years: 2022-2024
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Galaxian Repair Log

Issue #1:
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Game plays, but only the stars, player's ship laser, and bombs from the Galaxians are visible.

Resolution:
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Sounded like a classic 6L color PROM issue. Sure enough original chip was bad (very little life using the probe), so socketed and replaced it. Game now displays all of the graphics.

Issue #2:
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Some sounds are missing, like the intro music, Galaxian exploding, player laser shots, etc. Player ship exploding and background sound were working.

Resolution:
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Found a hairline solder crack on IC 8K pin 2 (74LS161), parts side of the board. That pin normally connects to 9K pin 2 and I found a repair of that connection on the solder side of the board. Testing shows the repair was good, but 8K pin 2 was still flaky. Didn't have a spare 74LS161, so running a wire (parts side) to 9K pin 2 resolved the issue. All sounds work again.

Scott C.
 
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