Re: Rev 4 mobo disk trashing mystery

["Michael J. Mahon" <mjmahon@aol.com>]

schmidtd wrote:
> I picked up a rev 4 B&H machine the other day.  Integer ROMs, raised
> power key, dark green slots, serial 27xxx something with 7930 date.
> It's temperamental as those machines tend to be - and I have some
> keyswitch rebuilding to do as well.  One problem is truly vexing me:
> it trashes track zero of any disk I feed it when booting.
>
> I have tried different power supplies, different disk controllers,
> different ROMs (I plugged in a set of Applesoft ROMs on a switchable
> card), and even swapped out every chip from a known-good mobo.  Still
> I get the same behavior: booting with the disk card in slot 6 causes
> disks to lose their minds.  They become unbootable, uncatalogable, and
> have to be reformatted (not just re-imaged) in order to be reused.
>
> What on earth might be causing this?

Have you tried swapping the DRAM?

-michael

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