Overclocked my gpu now my computer won't even power

[Diasho]

Yes, the classic overclocking worst case scenario. I'm running crossfire MSI Radeon HD 6950 Twinfrozr II's which I have unlocked to 6970's. On MSI Afterburner I cranked the voltage to around 1300 mV I think. I ran FurMark's burn in test and instantly my computer just shut off. Now when I press the power button I can't even get power to the thing. Literally nothing happens. I'm afraid to look in my computer because I think I might have melted everything in it and now it's a block of solid metal and plastic. Tell me what I did. I probably just wasted A LOT of money.

 

[rgd1101]

so, instead of doing it a small step at a time, you go all out the first time?
what your psu?
full system spec?

 

[Diasho]

so, instead of doing it a small step at a time, you go all out the first time?
what your psu?
full system spec?

PSU is earthwatts 650 watts
AMD Phenom II 975 x4 Black Edition
2 Crossfired MSI HD 6950's Twin Frozr II (unlocked)
512gb Sandisk SSD
M48A7T-E Asus Motherboard
8gb Corsair Vengeance DDR3
In short what I did was I followed a guide on this forum and I adjusted the wrong variable.

 

[rgd1101]

have you try unpluging the 2 6950 and just use the integrated gpu?