Stumped by POST Error

[rodger 1]

Mobo -ASUS P9X79 Deluxe
GPU - 1, EVGA GTX 580
Win 7 64 Bit
PSU - Corsair 1200

My system is 3 months old and was working perfectly. I am now getting a POST error, 1 long beep - 3 short beeps (indicating a GPU problem) then the screen goes black and freezes. I have tried everything that ASUS and EVGA can think of including flashing the BIOS and GPU but I don't have another mobo or GPU to swap around and test.

Here's the interesting part: If I clear CMOS I can get to the BIOS without the POST error. If I exit the BIOS without saving changes then I can continue to Windows and everything, including the GPU, works great. When I reboot, the POST error comes back.

Any ideas?

Thank you

 

[scout_03]

do a memtest or windows memory diagnostic

 

[JKatwyopc]

Have you tried replacing the CMOS Battery? It should be a CR2032 battery. You can pick one up almost anywhere you can buy batteries.

 

[Onus]

If replacing your CMOS battery doesn't help, check your memory remapping and/or shadowing options in the BIOS.