CMOS checksum error

Whitestar

Junior Member
May 27, 2007
17
0
0
I have the following setup:
-EVGA nForce 680i SLI, nForce-680i SLI 2xGbLAN, DDR2, 2xPCI-Ex16 Socket 775 Type A1
nVidia BIOS version: 2.053.74
Phoenix AwardBIOS v.6.00PG
-Display: EVGA GeForce8800GTX KO ACS3
-PSU: MIST 600W
-CPU: C2D E6700
-RAM: OCZ DDR2 2048MB Platinum XTC Dual Ch. PC2-6400 2x1024MB 800MHz. (4.5.4.15)
-Cooling: Thermalright Ultra120

My computer posts just fine. I hear the "good sound", 1 beep. Then the text about processor, memory and stuff comes up on screen, followed by the SATA-ports and what's connected to them.

But then comes the message: "CMOS checksum error - defaults loaded. And then the computer freezes. I can't do anything more, which also means I can't get into BIOS (Setup).

I think I've tried just about everything by now. I've tried to only have the following connected: graphics card, processor fan, Power Switch connector, 8-pin power connector, 24-pin power connector and just one RAM module (in DIMM Slot 0 closest to CPU). Still same error.
Tried moving RAM module to different slot, still same error.

The post code (if that's what it's called) on the mainboard display shows 7F.

No metal parts of the I/O shield are in contact with ports on the mainboard, and the holes in the mainboard all match up with the spacers the mainboard is resting on.

Then I tried the following. I put the CMOS pin in the Clear CMOS position, took out the battery, left the machine like that for about half an hour, then put in a new battery and put the CMOS pin back to original position. No effect. Still same error.

I'm beginning to run out of alternatives. Could the mainboard simply be defect? I suppose there is a chance that the RAM could have issues with the mainboard, but it doesn't sound likely.

Anyone have a clue?
 

Puffnstuff

Lifer
Mar 9, 2005
16,256
4,930
136
What about standoffs? Did you make sure that you only placed standoffs at the correct points on the mb backplane? Have you tried with the mb outside of the case?
 

Whitestar

Junior Member
May 27, 2007
17
0
0
Yes, like I said, all the standoffs match the holes on the mainboard.
Haven't tried to boot outside the case, though. Will try, thanks for the tip.