When the laptop is losing its date or time settings, or you are receiving a message CMOS Checksum Error, CMOS Read Error, or CMOS Battery Failure, the CMOS battery needs to be replaced. To do this, follow the steps below.
Disclaimer: Please follow the below at your discretion, as we will not take any responsibility for problems encountered or any damage that could occur.
Locate your CMOS battery
Open your laptop case and find the battery on the laptop motherboard. Verify that it is accessible and can be removed. in most case the CMOS battery exist beside the RAM or Wi-Fi card. Today, most laptop use a coin cell CMOS battery, like the CR2032 battery shown in the picture. If you are unable to locate your CMOS battery, refer to your laptop manual.
Removing the battery
If your laptop is using a coin cell battery, removing the battery is relatively simple. Use your fingers to grab on the edge of the battery and pull it up and out of the socket holding it in place. Some motherboards have a clip holding the battery down. If your laptop’s motherboard has this clip, you may need to use one hand to move the clip up and the other hand to pull the battery out.
Unfortunately, not all CMOS batteries are removable. If your laptop does not have a coin cell battery refer to your laptop manual.If your laptop’s motherboard have a soldered battery, you need to desolder the CMOS battery and resolder the new one.
Enter CMOS values
Once the CMOS battery is replaced, turn onyour laptop and reset time, date and BIOS values to the defaults. After the values have all been entered, make sure to save the settings before exiting. Many BIOS setups allow you to press a key (such as F10) to save values and exit all in one action.
If you continue to receive the error after following all the above steps, this is a sign of a more serious issue. The most likely causes are a bad motherboard.