3b1 won't even boot off diagnostics disk; PLEASE HELP!!! (any info)

[Augustine Cano]

Hello everyone:

When I got home yesterday my 2/67 3b1 had crashed.  There was a long message on
the screen with lots of registers (panic: kernel addr fault or something like
that) and then a HDERR message (EF:1).  I'll be more than happy to send the
whole message to anyone who might want more detailed information for some
detective work...  Or maybe somebody can enlighten me as to the meanings.

In any case, neither the hardware reset nor turning the power off (different
mechanical noises can be heard in the two cases) brings up the machine, no
matter what is in the floppy drive (diagnostics disk, bootable system floppy or
nothing).  The machine is out of warranty, so the quick and easy option (ATT
service) is out unless I have no other choice.  If ATT is going to charge me
$280 to swap the mother-board, I might as well buy another machine for parts.

Given the many power supply problems on similar machines I've been reading
about lately, the first thing I did was to check the voltages at the ribbon
cable that goes below (to the mother-board) and at the power connection to the
HD.  +5, +12 and -12 seem to be ok.  There was no visible damage anywhere.

The symptoms in more detail: When powering up, the mechanical noises of the
first few seconds sound normal, while the 4 little squares on the top left of
the screen appear.  Then instead of clearing the screen to display the loader
message, more squares appear, each accompanied by a repetitive noise.  That's
it, nothing else ever happens.  After a hard reset, the only difference is that
the first few seconds of normal sounds don't happen.

Some hypotheses: Since neither the floppy nor the HD work, I would venture to
say that the problem is not in the respective controllers or cables. Am I
wrong?  The voltages at the ribbon cable and the correct intensity squares on
the screen seem to absolve the power supply.  Am I correct?

I don't have the hardware repair manual and have been unable to find one
locally.

Some specific questions:

- Has anyone had this kind of problem before? How was it solved?

- Can someone suggest a sequence of tests that would narrow down the problem?

- Does anybody in the DFW area have the hardware repair manual that I could
  borrow/rent while I try to get this fixed?

- Failing that, anybody has one for sale? (as cheap as possible, please)

- If, for lack of resources or information, I can't get the job done, what are
  the cheapest places for parts and/or service? (I am aware of TRC, Var-tech
  and DDS, whatever their new name is; I plan on calling all of them on Monday)

- Is there anybody willing to part with a very cheap 7300/3b1 (working or not)
  that I could use for parts? A non-working parts machine would not solve the
  problem now, but in case of future problems, I'd have a machine to keep
  using, temporarily.

Any information, help, referrals, suggestions, etc... will be enormously
appreciated.  I guess I just found out how much I depend on that machine.  I
have to get it back up as soon as possible.  If there is interest, I'll
summarize.

Thanks in advance...

Augustine Cano    canoaf at dept.csci.unt.edu