Thanks.

 

No, it is not under warranty.  I'll boot it with the case open next time.  As far as I can tell, there is good air flow when it boots quietly.  This happened once several months ago, and then was fine until now.

 

If it turns out to be the fan, I will replace it.

 

Clear skies, Alan

Booting up with the case open quickly revealed it is the fan in the power supply.

 

Thanks.

 

Clear skies, Alan

Have you tried to blow it out with canned air? alot of times when they get caked up with dirt they will make all sorts of noise. It is a good habit to be in to clean out all the fans and the inside of the computer every few months with canned air. I do this at least once a month.

Thanks.  Yes, I clean the case on a regular basis, including the fans.  Cleaning did not help, and a new power supply turned out to be reasonably cheap.  (Otherwise I would have opened the power supply and tried to simply replace the fan, or re-oil it.)

 

We have two house rabbits, so cleaning out the computers is extra important.  Bunny fur is rather light and tends to "get around."

 

Clear skies, Alan