Bios Checksum Error - Troubleshooting

[Aardobard]

On Sunday I did a clean install of Windows XP64.

Sunday night, I flashed my bios from 0901 to 1002. This allowed me to OC to a 400x4 FSB. After working on the stability for a while and making some progress, I decided to celebrate and play a little FEAR.

After a couple of crashes, I set the entire bios to known stable, stock settings so I could play for a while. That worked fine.

I have had to correct my Windows clock twice today, as I noticed it was wrong.

While websurfing (mostly on OCN) my computer locked up (no BSOD, just a 'hang').
I rebooted and it happened again within a couple minutes.

I've been suspecting a RAM problem for a few days, but no errors were reported in testing (Memtest+86) over 10 hours. With that in mind, I decided to try another known stable setting that would underclock my RAM a bit and allow me to troubleshoot it that way, but the boot failed.

I reset the bios to stock values again and this time, after the ROMSIP update, I got (and keep getting) the following message:
Award Bootblock v1.0
Bios Checksum Error

I have cleared the Bios on the mobo with the battery removed. Same Error.

The Google knowledge base seems to think it is either a bad mobo battery or bad RAM. At this time I'm inclined to think it's the battery based on the clock needing to be reset and the unlikelihood of two separate sticks going bad at the same time.

I apologize for the length, but I have changed a lot of things recently and didn't want to leave out any pertinent info.

Is there something else I should check/try?
[Edit I've already tried different combos of slots and single RAM sticks...]
[Edit Update - I metered the battery and it's showing proper volts.]

Thanks in advance
P5N-E SLI * bios 0901 * e7200 * 2x2GB Gskill 800MHz

 

[major53]

Aardobardtheir it is a easy way to find out if battery is bad, if you can check it with a volt meter if you can get your hands on one,also could just replace it ,most battery's are 3.6 volt,also you could try one of you ram stick to see if it will boot up correctly.

how long have you had mobo and ram? also was it working ok before the bios flash.

 

[Aardobard]

First of all, thanks for the response. I did check the battery with a DVM and it seems to be good. And I have attempted to boot with each RAM DIMM individually, even trying different slots.

One thing I am thinking... I use a wireless USB keyboard and mouse, a USB headset, and a USB cardreader. All of which have given me issues over the last two weeks. In fact, I was sure my keyboard was toast and that it's matching mouse was giving up until I plugged them into another computer and they are working flawlessly.

Looking at the symptoms again, random instability (looks like RAM), Bios issues (could be faulty RAM), USB instability, and resetting the onboard time, it's almost either got to be the mobo or the PSU.

Time to break the Digital Volt Meter (DVM) and eliminate the Corsair PSU.

 

[major53]

Aardobard do you have a ps2 keyboard and mouse.also if you list pc part it would help.