gerryt@ wrote:
> Huge wrote:
>> 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 ...
>
> Probably not temperature problem.
> I have an Ultra 2 that behaved in very similar fashion.
> Found a PS on eBay, replaced the old one, and all was well after.
> Just got a FC/AL switch from eBay and its doing the same thing!
> Switching power supplys are on my grrr list : >
>

Gerry is probably correct in replacing the power supply, but I'd like to
add to another possible reason. It seems when the computer shuts down
suddenly and comes back up again right after recycling the power is
usually some short after the output stage of the power supply bringing
the power supply to use it's short circuit protection. Reseting the
power supply will bring it back up again. This could be caused by a
leaking capacitor on the output stage of the power supply or even on the
motherboard. Again as Gerry suspected, the first place to try is
replacing the power supply, as usually most computer problems are power
supply related.

Paul