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Re: Rev 4 mobo disk trashing mystery



schmidtd wrote:
On Apr 22, 11:38 pm, schmidtd <schmi...@my-deja.com> wrote:

On Apr 22, 11:05 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:> So, just to summarize, the same procedure, same disks, same drives,

same controller, sam power supply--all work fine when only the main
board is different?

Yes.  One more difference: the board I'm testing is bare naked,
sitting on a non-conductive surface.  The parts I'm swapping in and
out are in an Apple resting comfortably in a case.  Grounding, maybe?

Yep, that looks like the problem.  I buttoned everything back up, and
now things are looking much better.  Disks are booting, and the
keyboard is decidedly less flaky than before.  Still flaky, to be sure
- but that's the nature of this particular beast.

BTW, I'd suspect 0.1uf bypass caps and electrolytics--on both the
main board and the controller board.

If you have a 'scope, looking at the power, particularly near
the disk controller slot, would be interesting.

-michael

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Home page:  http://members.aol.com/MJMahon/

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