CMOS checksum invalid

[0Tyler9]

hello, when i boot my pc it says cmos checksum invalid. everyone says to reset cmos, i did. everyone says to update the bios and it is the newest one avaliable. i think it may be related with these two jumpers on my motherboard which i may have moved in the past. my pc also turns on whenever i turn on my surge protector its connected to for some reason, and i would like to know how to fix that too, or if its related to the other problem i am having. i also attached the pictures of the jumpers so you can tell me if they are right please. thanks

[Sneha_01]

Hi @0Tyler9,

Welcome to HP Support Community.

Thank you for posting your query, I will be glad to help you.

The "CMOS checksum invalid" error generally indicates that the CMOS (Complementary Metal-Oxide-Semiconductor) battery, which keeps the BIOS settings and system clock running when the PC is powered off, may be failing or that there’s a problem with the BIOS settings. Let’s break down the troubleshooting steps for your issues:

1. Addressing the CMOS Checksum Invalid Error

Replace the CMOS Battery:

• Battery Type: The CMOS battery is usually a CR2032 lithium coin cell battery.
• Replacement: Purchase a new CR2032 battery and replace the old one. This battery is often located on the motherboard.

Reset CMOS Settings:

Clear CMOS:

1. Power off your PC and unplug it from the wall.
2. Open your computer case.
3. Locate the CMOS battery and the CMOS reset jumper on the motherboard (often labeled as CLR_CMOS, CLEAR, or JBAT1).
4. Move the jumper to the “Clear” position (typically from pins 1-2 to pins 2-3) and wait for about 10 seconds.
5. Move the jumper back to its original position.
6. Reinsert the CMOS battery and power on your PC.

BIOS Reset:

1. If you cannot clear the CMOS with the jumper, you can also use the BIOS menu to reset to default settings once the system boots. Access the BIOS setup by pressing the designated key during startup (usually F2, DEL, ESC, or F10).

Update BIOS:

• If your BIOS is up-to-date and you’re still experiencing issues, re-flashing the BIOS might help. Follow the instructions on the motherboard HP website to re-flash the BIOS using their recommended utility.

2. Addressing the Surge Protector Issue

Power Settings:

• BIOS Settings: Check your BIOS settings for power options. Look for settings related to "Power On After Power Failure" or similar. Ensure this is set to your preference (e.g., "Off" if you don’t want the PC to turn on automatically when power is restored).
• Power Supply Unit (PSU): Ensure that your PSU and surge protector are functioning correctly. Sometimes, a faulty PSU can cause unexpected power behavior.

Inspect Power Connections:

• Ensure that all power cables are correctly and securely connected to the motherboard and other components.

3. Check Motherboard Jumpers

Verify Jumper Settings:

The configuration of motherboard jumpers is crucial. Here’s a typical setup:

• CMOS Clear Jumper: This jumper is used to clear the CMOS memory and reset BIOS settings. It usually has three pins with a jumper connecting the first two pins by default.
• BIOS Recovery Jumper: Some motherboards have a BIOS recovery jumper for re-flashing or recovering the BIOS. Ensure it is in the correct position.

Refer to the Motherboard Manual:

• Check your motherboard’s manual for the correct jumper settings. If you can’t find the manual, you can often download it from the motherboard manufacturer’s website.

Correct Placement:

• Pins Configuration: Ensure that the jumpers are correctly placed according to the motherboard’s specifications. If you suspect that you moved them, restoring them to their default position is essential.

I hope this helps.

Take care and have a good day.

Please mark this post as “Accepted Solution” if the issue is resolved and if you feel this reply was helpful click “Yes”.

Rachel571

HP Support