According to Huge <huge@huge.org.uk>:
> My Sun workstation (an Ultra 60) has started powering itself off after
> about 20 minutes of use. There's no warning, no error messages, nothing
> in the logs, it just powers down. If you switch it off and on again, it
> comes straight back up, but does the same thing after a much shorter
> time. On the third attempt, it didn't even have time to boot up before
> doing it again.
>
> I have a suspicion that it's temperature related, therefore. Any
> suggestions as to where to look? I haven't had a chance to take it to
> pieces yet (although I have downloaded the service manual (Ghod bless
> the web)). I initially assumed it was a faulty power supply, but I
> wonder if some of the fans have failed ...

This is in the home, not in a specially controlled machine room?

If so, it is possibly an accumulation of housedust -- and in
*my* house, cat fur as well. Shut it down, take it outdoors, and hit it
with compressed air to blast the dust out of various places --
especially the power supply air cooling paths. This is probably better
done in humid times, as it decreases the chance of static discharge from
the airflow damaging the system. And -- it presumes the availability
of compressed air at home. Though I have used dusters made with CO2
cylinders, though they tend to be more expensive as the refills cost a
lot more than they should.

If you do it *indoors*, be sure that you, and anyone else
around, wears a dust mask, because the room will fill with a cloud of
dust, which will hasten the development of problems in other machines
already in service.

The SS5 tends to accumulate dust between the left side and the
power supply. Other systems in other locations.

Also -- I've had a 140 MHz Ultra-1 fail in similar mode because
the fan mounted over the CPU was dead. I was able to bring it back to
life for a short time by disassembling and re-lubing the fan, but the
final cure was to get a replacement fan of the same dimensions and
voltage, but ball bearings instead of sleeve bearings. Take out the old
fan, measure its dimensions (note dimensions both in inches and in mm,
to help finding ones in catalogs like Mouser, Newark, or Digi-key.)

> I've bought a whole new machine on eBay - it was half the price of a
> new power supply, so I should be able to assemble an entire working
> machine out of the two, by a process of elimination, if all else fails.
> (We also have three U60's in the "demise" pile at work, but it's a royal
> pain getting them home. They're too heavy to carry on the train, and
> driving into London is the pits.)

Perhaps bring home selected parts, like power supplies and
fans?

Good Luck,
DoN.

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