CHOS Checksum Error

[milkolate]

HELP!!!
I want to fix my PC at home. Whenever I start it up, it has "CHOS Checksum Error - Default" press F1 to continue. How do I fix this?

[FuturePilot]

BIOS checksum error?

[Ireclan]

First of all, are you sure the error isn't "CMOS Checksum Error - Default press F1 to continue"?

If so, this means that the contents of your CMOS has been altered from last time it booted. I'd say you need to replace your CMOS battery, but that's just me. Can you boot the computer if you press "F1'?

[milkolate]

It's really CHOS not CMOS.. when I press F1, it does boot properly, but I want to remove the problem

[FuturePilot]

I'd try replacing the battery. And perhaps the BIOS is a little quirky. When my BIOS got messed up, you could barely read anything due to the RaMDomlY CapITAliZeD LeTteRs and
the odd character ڀhere and there. So maybe it really does say CMOS but looks like CHOS instead. Perhaps a BIOS flash is needed?

[milkolate]

1. How do I replace the BIOS battery?
2. How do I do a BIOS flash?

[FuturePilot]

The battery is one of those flat button batteries. It's on the MB somewhere. You'll have to take a look around inside your computer because it's usually different on every computer.
I'd just try that first and see if it takes care of that error. If it doesn't and you want to try and flash the BIOS you'll need to either go to the computer manufacturer's web site and look around for updates for your model, or if you built it yourself have a look around the mother board manufacturer's site.

[lisati]

I first wondered about CHOS and CMOS too.

The setup on my desktop has an option on one screen which lets you reload optimized defaults. That might be another option to check as well if your computer has it.

[Tundro Walker]

I don't think you'd have to reflash the bios...usually just removing the old battery, waiting a good minute or so, then tossing the new one in works. Make sure your computer is unplugged (or at least your power supply switch is off).

It usually goes without saying, but I'll say it anyways, make sure you touch something metal, like the computer case, to discharge any electro-static build up you may have acquired while wandering around the house. Try to stay in contact with a piece of metal while working on the comp. I usually just rest an arm on the computer case while I'm fiddling around. Keep the cat away from the computer while you're working on it ("nice kitty! ZAP!), and preferably, you'd be standing on a non-staticy surface, like the garage floor or kitchen tile (or rubber mat).

You should be able to get a replacement battery pretty easy at Fry's or Best Buy or CompUSA. Just take the old one in, and if you can't find a match for it, try asking for help. There should be some computer-oriented person who knows where the batteries are.

After boot-up, you'll have to go into the BIOS and do up your settings again, but they'll stay put this time. The new battery should last you a good 5 years or so, depending on how much you use your comp.

[milkolate]

Oh no, I don't know what the BIOS/it's battery looks like

[smoker]

normally a small silver disc like this:

sorry! pic below

[smoker]

small silver disk like this:

[PatrickMay16]

I had a similar error on my computer when I updated the bios. I fixed it by clearing the CMOS... look at the instructions for your motherboard on how to do that.

[Lux Perpetua]

I recently had similar errors on my laptop. It only happened after I had used my computer plugged into a power outlet on a cruise ship; as soon as I got off the ship, the problem went away. It complained of a CMOS invalid checksum on booting, and the system clock would be reset. After setting the clock, I could boot it and use it normally, but I had to do it every time. The only explanation I can think of is that the outlets on the ship used nonstandard voltage/frequency. They also didn't charge my phone properly, so this seems likely.

I'm not sure how much of that you can use...but there you have it.

[tpg]

I had something like this recently, too. Although, before the "CMOS checksum error" began to pop up every time, it would just change the system time to a seemingly random time & date.

Replacing the battery fixed all the problems.