EVGA 680i SLI mobo F7 Error code

Okay so I was OCing my pc, got it to 3 ghz stable but running hot, went down to lower the voltages and clock speed a bit to 2.8 ghz, rebooted and screen was flickering a bit, restarted, raised some voltages that I had lowered before thinking changing them was a good thing, rebooted, same problem, pc froze and crashed though, went into bios, it froze and crashed in bios, rebooted, got error code 01. then rebooted got FF and it would just sit there, nothing would come up on the screen. So I reset cmos, now trying one last time to do that, 4th time, and I get error 7F no matter what in the end now. as the pc boots up it goes through numbers and if anyone knows the standard beep it makes in booting, i get a longer beep than usual around when it is at 25 and 26 on the error code, but it keeps going and stops at 7F, any clue what might have happened or if things are royally screwed? clearly 7f is a posting error but if clearing cmos doesn't work then something should be messed up, but i never had any high voltages or anything. Also perhaps someone could tell me how to remove the cmos battery? I have been using the jumpers but maybe that just isn't working? I could never seem to get the battery out though and don't wanna break the pins holding it in.

thanks for the possible solution. now if only I had a pc to test my gpu in. also it's so old I doubt the warranty is still there, nearly 2 yrs old now. plus i decided to take my pc apart and clean out the dust and broke a pin off of the cheap plastic fan/heatsink. I am so sick of tech, it is not simple or easy at all.