Do you have a dead motherboard battery? I too have dealt with expired or failed motherboard batteries and know the headaches it can cause.
In this article, I will explain what a motherboard battery is, how it works, issues that can arise due to a faulty or failed battery, and even how to save money and replace it yourself.
What is a CMOS Battery
TheCMOS (Complementary Metal-Oxide Semiconductor)or motherboard battery works as anRTC (Real-Time-Clock)on your motherboard. The CMOS acts as a battery-powered semiconductor chip inside your computer that stores theBIOS settings.
These include the system clock and hardware configurations likefan speeds,boot order,overclocking, etc. for your computer to startup and load correctly.
All this information is maintained with a near-quarter-sized lithium battery located directly on the motherboard of the computer.
Corruption of CMOSis unfortunately very common. Theaverage lifespan of CMOS batteries is 3 to 10 years. If you use your computer more often, thebattery will last longer.
If you go a long time without using your computer, the battery is constantly drained to preserve all that important startup information.
How to Detect a CMOS Battery Failure
Although the battery can outlive theusability of the system, it does fail over time. Here are a few signs that point to a failing CMOS battery:
Troubleshooting a Dead CMOS Battery
To verify that the battery is the issue we will need to narrow it down. We can try first by resetting the CMOS. After that check if the battery is dead using a multimeter and then replace it with a new one.
Before taking your PC apart, check the motherboard’s user manual for the exact location of the CMOS battery and the Clear CMOS jumper/header. Additionally, you are going to handle internal PC components so, ensure toground yourselfbefore proceeding
Reset the CMOS
This is a very simple task that requires a #2 Phillips-head screwdriver. Use it toremove the side panel of the caseand then later short the CMOS jumper.
Follow the steps below,
Check and Replace the CMOS Battery
Now that you have verified the issue is not due to corrupted settings, you may proceed with the troubleshooting by testing the CMOS battery. For that,
Can a Motherboard Run Without a Battery?
Technically,YES. Removing the CMOS battery will allow your computer to run however, you will lose the date and time settings, the computer will boot with default BIOS settings or you will have to choose the drive that the OS is installed every time you start your computer.
Will Removing the Motherboard Battery Reset BIOS?
This is an excellent question I get asked a lot. The short answer isYES. If you remove the battery, wait approximately 5 minutes and then reconnect it, it willreset the BIOS.
Can a CMOS Battery Cause a Black Screen?
A faulty battery removes all of your boot settings. It is very possible to see nothing but ablack screen when bootingup a computer with a dead CMOS.
For example, if you have a secondary video adapter that your monitor is plugged into and your BIOS has reset to default settings, your onboard video would be the new display and not your primary video adapter.
