ASRock extreme 4 Z77 Motherboard
i5 3570K cooled by a Corsair H80i
16 GB Corsair Vengence 1600 RAM
2 EVGA SC GTX 660's in SLI
500 GB SeaGate 7200rpm hdd
OCZ Z Series 1000W Gold Power Supply
I recently overclocked my i5 3570K to 4.2 Ghz using an online overclocking guide. Following the guide I downloaded CoreTemp to monitor the cpu. I then changed the settings in the BIOS. I exited the BIOS and heard a pop sound. The computer shut itself down completely (Fans off, Lights off) for about two seconds and then turned itself back on. It booted to the Windows splash screen and I got a BSOD. I cleared the CMOS to return the BIOS back to factory settings. Computer still booted to Windows splash screen and then BSOD. There is no stop code on the BSOD, and no codes appear on the onboard debug screen on the motherboard. The BIOS also recognizes the hdd in the BIOS (makes me think the hdd is ok). So far I have run system restore, startup repair, and last known good configuration with and without the Windows install cd. I have also run several boot record fix commands in the command prompt. None of these have fixed the issue. Does this sound like a cpu or psu issue, even though it boots all the way to the Windows splash screen. Any insight would be greatly appriciated.
I've had this happen to me twice, on two old motherboards (about 2 years ago) after overclocking (probably due to my inexperience at the time). The first time, I heard the system make a light pop sound on boot up, the machine powered on, fans on etc, but nothing else. It would just sit there with nothing on the screen, not even hitting post. It turned out I had blew the VRM and after exchanging the motherboard, all was well.
The second time, I heard the pop and the machine wouldn't even power on at all. I took the assumption I had killed the PSU, and I later learned I was correct when I swapped it out. Again, my stupidity, it was a fairly crappy supply, unbranded etc (I've since learned my lesson and only look to reputable brands). So saying that, OCZ, as far as I'm aware, make very high quality supplies, so it'd be a mile away from the crap I had.
I would say it's likely you've just overworked the motherboard. I would suggest, if it's at all possible, try each component in a different machine (say a friends) - that's something I did at the time, in both my experiences. It will help you determine if the problem is with any of the other components and so on.