ludi wrote:I've had two PSU failures, one of which was a cheap CompUSA store-brand from waaaayyy-back-when that emitted loud *SNAP* and never breathed again, and the other was an Antec that began emitting the noises and odors of corona discharge and was pulled out of service immediately. Both were replaced under warranty and there was no further damage to the respective computer systems.
However, a failing switchmode power supply can send its output voltages wildly out of spec or begin passing AC voltages into the DC output, and either condition is capable of destroying everything downstream if the output protection circuitry is inadequate. Not common, but possible.
Ah yes, weren't some Bestec units notorious for this several years back? Sending 120V right into the motherboard (or standby line?).
As for cleaning PSUs... I've spent summers cleaning out PCs at work. Take a compressed air blower (120V), pull off the front plastic grill on the PC, push things out of the way, and blow air everywhere (while wearing a mask, hopefully). So satisfying seeing the green silicon of the motherboard, rather than the greenish/grayish of dust all over. Amazing what comes out of those things sometimes. I don't recall the Antec 300 ever getting terribly dusty though (although I since gave it to a friend).