Dying machine?

[Mark S. Mersereau]

In article <1057 at kosman.UUCP>, kevin at kosman.UUCP (Kevin O'Gorman) writes:
> ...
>
> Then, I was getting ready for Xmas, and decided that since this thing
> sits with its back to the common areas in my house, that I would clean
> up the cabling a bit.  I had the power off for several hours while I
> did this.  It took me a large number of tries to get it running after
> that interval.
>
> This was not the sticktion disk troubles that others have reported: I
> could hear the disk spinning up. At first, the screen showed a pattern
> that looked like a rectangular spider web with a couple of random
> mouse tracks running across at two places.  A reboot got to the normal
> screen test-pattern and then a permanently blank screen.  Several more
> reboots got further and further.  Another got to UNIX, with crashes
> within the first few minutes.  Finally, after power had been on for
> 30 or more minutes, I got a reboot that seemed to be stable.  Then a
> bit later, I got the first honest-to-goodness kernel panic I've seen
> in years.  Eventually, it got stable, and has been running without
> crash for about a week.
>
> Sounds to me as if something's temperature sensitive, and likes to be
> hot.
>
> Anybody have any ideas about how I could go about finding out what it
> really is?  I would like to just chuck the part, whatever it is that's
> doing this.   I'm pretty handy with tools, though I don't have more than
> a soldering kit, multimeter, and the usual pliers and things.

     I'd also like to find out what's causing this problem, since my
machine seems to be similarly plagued.

     I bought my 3b1 new about 2 years ago and it has been running
more or less continuously ever since. Over the past year, I periodi-
cally powered it down and opened it up for cleanings and repairs
(e.g., hard disk drive replacement, power supply replacement, static
eliminator spring  adjustment, WD2010 installation, etc.).  Occasion-
ally, after I put the 3b1 back together and switched on the power, the
screen would come up full of thin horizontal cells -- a `rectangular
spider web' -- instead of showing a normal boot load in progress, and
all four of the motherboard-mounted LEDs would be on.  Sometimes this
was accompanied by a 5 pulse per second chirping sound, regardless of
whether the phone lines were connected.  Immediately hitting reset
caused no change; but once in a while, if the machine was left running
for several hours and then reset was hit, the screen would clear and
the system would boot.  I adopted the recovery method of switching the
power off and on until the machine came on without the chirping sound,
waiting for several hours, and pressing reset.  It usually booted suc-
cessfully once it got going, but a few times it would fail with kernel
panics.  Re-opening the case and re-seating any connectors I had
disconnected during the repair always corrected the kernel panic prob-
lem.

     Before I replaced the original 40 Mbyte Miniscribe drive, reboot-
ing the system after it had been shut down for repairs or cleaning was
frequently met with the above failure (i.e., a rectangular spider web
on the screen and a reset button that had no effect). After I replaced
the drive with a Micropolis 1325, I was pleased to find the problem
had gone away ... until last week.

     After opening up the 3b1 last week to adjust a vibrating static
eliminator spring and to install a WD2010 disk controller, I haven't
been able to get it to boot since. The rectangular spider web is back.
On a tip from the originator of this discussion, Kevin O'Gorman, I
replaced the power supply with a brand spanking new one, but the prob-
lem persisted.  What to try next?

-- {decuac,gatech,necntc,sun,uiucdes,ukma}!rayssd!msm
   msm at rayssd.ray.com