Problem with CMOS?

Question

my computer said CMOS Checksum Error. And I don't know what it is. Can someone explain it to me.

Answer 1

A checksum is computed as an error-detecting code, to protect the BIOS settings stored in the CMOS memory. Each time the system is booted this number is recomputed and checked against the stored value. If they do not match, an error message is generated to tell you that the CMOS memory contents may have been corrupted and therefore some settings may be wrong. BIOSes react in different ways to encountering this sort of error. Some will warn the user and then continue on with whatever settings were in the CMOS. Others will assume that the settings that were in the CMOS were corrupted and will load default values stored in the BIOS chip "for safety reasons". The error message will indicate which your system is doing.

The most common cause of checksum errors in CMOS is a battery that is losing power. Viruses can also affect CMOS settings, and motherboard problems can also affect the stored values.

You probably need to replace your internal battery (looks like a big watch battery) Write down all your BIOS settings, replace the battery, then boot up and set your BIOS settings to where they were.

Some additional links below with additional info.

Hope this helps

Answer 2

this could be as the other answerers have said a problem with the battery on your computers motherboard.
but first just go in to the system BIOS and see if the date and time are correctly set. if yes exit BIOS, then power down the computer turn off at the mains (not just the front panel).
wait 30 seconds then power on the computer mains supply then the system switch however yu normally do. (i only sya that because my system is set to come on in a range of several different ways).
Now go back into the BIOS, if the system date is reset to anyother date other than the day of the test normally way into the past (the first date the bios has programmed) then the CMOS Battery is dead. Which requires your computer to be powered down. you then need to open the case and locate the button cell battery on your mother board. The battery is normally a 2025 or 2032 button cell (20mm x2.5 or 3.2mm). now you have located the battery type in your computer carefully making sure to "GROUND or EARTH" yourself before you touch the components in your computer. to Ground your self either use a special Anti-Static Wrist trap or you can leave the computer plugged into the mains with the switch on the outlet in the off position and just touch the bare metal on the inside of your pc whilst removing the battery.
if you have a battery of the same type in your home then replace the battery. if not then go to the store and buy one.
now repeat the grounding procedure and replace the battery.
close the case on your computer, power up, go into bios and set the date and all the other essential settings for your system.

save the changes and exit bios, allow the system to restart and boot to your operating system. and the job is done. problem solved.

on the other hand an extremely remote possibility is a malicious piece of computer code such as a worm or virus, so run a full sytem scan as soon as you possibly can.

Answer 3

check the CMOS battery first..may be it lost it power...replace it with a new on.

Answer 4

Normally your system need to change date & time to perform this fix. if you persist the same problem. you better change the battery of your mainboard.