Saturday, November 18, 2017

Star Rider repair video (Ed Beeler's second CPU board!)

Here's another Star Rider CPU repair video.  This was a very challenging problem to solve!



FALSE ASSUMPTIONS ABOUT CAUSE OF PROBLEM:
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- turning on board while it was wet damaged something
- cpu was bad
- rom was bad
- 74LS245 was bad
- an unknown malfunctioning component on the board was interfering with the data bus

ACTUAL CAUSES OF PROBLEMS:
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- CPU RAM was bad (first problem)
- Two traces on the PCB were broken, causing corruption on both the data bus and address bus. (second problem)

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