Smoke from mobo, before turning it on?

G

Guest

Guest
1st build:
fx 6300
radeon hd 7850 gpu
asrock 970 extreme4 mobo
wd blue 1tb HD
nzxt gamma case
sentey ERP-650w psu

I assembled everything, then hit the power switch on the PSU. Immediately, a wisp of smoke rose from near the 24 pin ATX connector on the 'board. I hadn't even turned the board on.
I replaced the board with the same model, and this time breadboarded just the board, gpu, cpu, and psu. All worked fine, fans spun, etc. But after assembling in the case, and turning on the psu, the same thing happened. Smoke rose without even turning on the motherboard.

I've been desperate for solutions, and have 3 guesses

1. Bad psu brand?
2. Like a fool, i used the case screws instead of motherboard standoffs, maybe a short?
3. oxidation on psu pins?

Any suggestions?
 
G

Guest

Guest
It would be very hard for me to get another board.
Do you think I do some soldering work on the 24 pin connector?