TWGS cache test failed and how to fix it?

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August 28, 2017 - 4:32pm
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aigeek
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TWGS cache test failed and how to fix it?
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I have an Apple IIGS ROM01 w/ TWGS (TransWarp GS) 7MHz / 32K Cache, when it's cold booted, it can work smoothly.

But when it get hot or reboot, it will get Self-Test **Failed**3 on step "Cache RAM".

when hot reboot after TWGS self-test failed, got the error code $0046.

I had try to replace all three cache chips with new set of 25ns, but no lucky.

How can I do?

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August 28, 2017 - 6:29pm
Keatah
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Last seen: 1 year 2 months ago
Joined: May 27 2009 - 01:37
Posts: 1002
Re: TWGS cache test failed and how to fix it?

Simple easy things to try are to reseat the ram chips, and connectors. Be sure they're clean. Then replace the ram chips 1 at a time till it fails. Don't forget to clean the 50-pin connector and processor ribbon cable.

If that doesn't work then inspect and resolder any questionable joints.

Check for heat sensitive parts. I wonder which part fails when it gets hot. Freeze-spray could help here.

Then consider breaking out the DMM and Oscilloscope and get into real electronic troubleshooting.

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