What happened?

[jaiello]

Last night I took a computer out of my equipment closet so I could install Ubuntu 11.10 on it. I opened it up to make sure that everything was there and used some compressed air to blow out the dust. I plugged it in and sparks flew. There was a series of sparks and loud pops and the smell of burning something. I immediately unplugged the machine and went to bed figuring that I fried the MB. This morning I plugged it in and to my surprise it booted just fine. No problems at all. I can't find any issues on the MB by eye and everything checks out. So what happened? I think I dodged a bullet. The machine has been sitting here running for more than an hour and Ubuntu installed no issue. Did I just get lucky?

 

[Transfusion]

If it was from the PSU, by all means, replace the PSU. Loud pops could mean blown/leaking capacitors-make sure you check if any caps are blown from the bottom. I had an MSI AMD 760G chipset motherboard with a lousy Chinese 350 W PSU-I plugged it in, it started all by itself, and a steady stream of sparks started flying from one single resistor near the ATX power connector. I noticed it was posting It wouldn't boot up immediately after I replaced the power supply. I took it out yesterday out of curiosity and lo and behold, its up and running now with an Athlon II X2 240 OCed to 3.80GHz. I noticed the resistor connection was rather discolored and greenish. You and me probably got very lucky.

 

[jaiello]

I don't think the sparks came from the PS. I think that the compressed air somehow caused the problem to occur but for the life of me I can explain why.

 

[ChippyUK]

Maybe there was a small piece of thin wire that was broken off from the case or something that flew over several connectors when blown thus causing the mini sparks.

Although it may not have fried something serious to affect the general operation of the machine, I would check the sound/network/video and other integrated hardware to the motherboard.

 

[Davegod]

usually a little bit of water comes out when I've used those cans of compressed air