New MB - blown capacitor on first boot - bad PS or MB?

[Jeraden]

I just got new parts in to put a new computer together and already something went wrong. My first attempt at booting up was met with a snap-crackle-pop as a capacitor blew up, partially melted, and started smoking. I'm currently waiting for an RMA on the board to exchange it, but want to make sure the same thing doesn't happen again.

I'm powering it with a brand new 330w powersupply. Is my problem likely just a bad motherboard or could it be a bad powersupply? When I get a new board, I can try an older power supply on it to make sure it works, but at some point I'm going to want to try the new one again. I don't want to end up frying the board again if the PS is bad. I can try the new PS on my old computer, but again, I don't want to fry that board too.

Just wanted to see if people think a bad PS or bad MB is more likely to have caused the blowup?

 

[Buz2b]

Most likely a bad MB/capacitor. The MB regulates the voltage it receives and works with the capacitors to smooth out the flow. Obviously there was a breakdown somewhere in that process. If you are still worried you can probably get a local shop to test the PS for you or Antec makes an ATX PS testor that is only about $14. I got one from CompUSA. It is fairly basic in that it just tells you if the PS is good or bad, but you can also use a multimeter and check a few of the voltages with it. I "don't leave home without it!"

Edit: One other thing you might want to check is to make sure that the bottom of the MB is not coming in contact with or shorting on the case or perhaps a standoff in the wrong position. That could cause this to happen also.

 

[chasM]

Bad capacitor. It may have been installed backwards. A short to the powersupply should pervent it from coming on at all.