CMOS Checksum Bad MS 790FX - GD70 First time PC builder


Nov 13, 2011
Hello! I hope you're having a better day than I am! lol So I brought this gaming PC a few months ago and its been working extremely well until now! It has been crashing, Blue screening, and doing bad things so I decided to switch out the ram. I've never done it before but I thought it would be easy. I got the same exact RAM as it had before, installed it, started up my PC than I came to a screen getting me a whole brunch of options and an error: CMOS Checksum Bad

A7577AMS V1.3 042709
AMD Phenom II X4 955 Processor
DRAM Frequency For DDR3 1333 (Unganged mode. 64 - bit)

1 AMD North Bridge Rev C1
Initializing USA Controllers Done
8192MB OK
USA Devices
SATA 5 Hard Disk
CMOS Checksum Bad
Press F1 to Run SETUP
Press F2 to load default values and continue

F11 to enter Boot Menu

THINGS I've tried:
Switching out the motherboard battery, pushing the reset button, changing the date/time in the BIOS, Unplugging, checking connections, cleaning, reading manuals

Maybe I should have let a professional install my RAM! :( I have a MSI 790FX - GD70 Motheroard. So if you could PLEASE send sometime using your amazing brain to help me solve this issue, that would be great! Thank you and have a nice day!


CMOS Checksum Bad usually means that the CMOS configuration has been lost. Follow the instructions by hitting F2 to continue. The next time it boots everything should work fine.

Your motherboard should have a Debug LED. What is it displaying? Page 2-21 of the manual tells you what codes should be displaying at any given time depending on where your system is in the boot sequence.

Check to your Clear CMOS button by pressing it a couple of times while the power supply is Switched off(turn the switch off at the back of the PSU just to be sure no power is going to the MOBO) to make sure that it is not sticking.

Also, make sure you have a good CMOS battery by testing it with a DMM(if you don't have a DMM you can take the battery to Radio Shack and they can check it for you).

Check both batteries. Just because you got a new one doesn't necessarily mean that it is good.