Sun Ultra 2 resetting itself (for your interest)

From: Christopher Tidy (christopher.tidy_at_gmail.com)
Date: 10/26/04 

Date: Tue, 26 Oct 2004 01:00:59 +0000 (UTC)

Hello everyone,

A few months ago I asked a question here about why my Sun Ultra 2 was
resetting itself. I've just got to the root of the problem and I thought
I'd post the solution here in case anyone else is in a similar situation.

The first symptom was that numbers would fly past on the screen, then
the machine would dump core and reset itself. It would reboot and work
normally for what seemed like a random period of time. /var/adm/messages
indicated that an alignment error had occurred and recorded "BAD TRAP
type=34". The core dumps became more frequent to the point that they
were occurring every hour or two. Then the machine started to switch
itself off - no core dump, it would just switch itself off. It then had
to be switched off at the wall before it would restart. Sometimes it
began to boot of its own accord when it was switched on at the wall. A
day or so later the computer switched itself off so often that it was
impossible to get it to boot properly.

I suspected the power supply so I took it to a friend who is brilliant
at repairing electronic equipment. He suspected the power supply
capacitors and tested them using a special ESR meter. Having identified
a possibly suspect one, I ordered a new one and soldered it into the
circuit board. The computer now works fine - no switching off or core
dumps at all.

The capacitor was rated at 16V 1000uF 105degC and was located near where
the wires exit the power supply. I had to buy a bag of five at 43 pence
each, and I replaced three others of the same rating, but that's a cheap
fix! If anyone else has a similar problem, it might be worth looking at
the power supply, although it might not be the same capacitor which is
faulty. It seems that fluctuations caused by a dodgy power power supply
can result in core dumps. If you're interested in electronics, an ESR
meter might be a cheaper solution than buying a new power supply. If
anyone wants more information drop me an email
(christopher.tidy@gmail.com or cdt22@cantab.net).

Best wishes,

Chris Tidy

Relevant Pages

  • Re: Tech Needed: White Water optical sensor not working
    ... The ONLY switch that is not working is the 1 optical switch (Disaster ... test out, but I can't test the 2 chips, could these be ... If so, then yes, your 7 opto board would be suspect. ...
    (rec.games.pinball)
  • Re: 19" LCD recommendations please
    ... > I have absolutely no problems with a 19 inch gnr at 1280x1024, ... > switch it between a Linux box and a now rather elderly Acorn RiscPC ... never did work out why but I suspect it was a sort of inverted ...
    (uk.comp.homebuilt)
  • Re: GFloat Rounding issue in DEC Basic V1.2-000
    ... Yikes! ... I don't suspect any compiler bug, but have you tried the latest version ... you may need to switch from FLOAT to DECIMAL in certain places ...
    (comp.os.vms)
  • Re: sed: how do i do this?
    ... > First, I'm not sure sed is the best tool for the job, but I suspect it ... Try this, Lowell: ... .* zero or more instances of any charcter ... for every line between regex1 and regex2, inclusive, switch the whole ...
    (comp.unix.shell)
  • Re: [PATCH] fs/locks.c: prepare for BKL removal
    ... On Mon, 20 Sep 2010, Stephen Rothwell wrote: ... I suspect the easiest thing is to leave Ceph out of this stage of your ... I'll switch lock_kernelto lock_flocksonce that exists ...
    (Linux-Kernel)