CMOS Checksum Error

[GraphicCard485]

I have recently got this issue in my laptop. My Laptop just shut down automatically and when booting it up, it won't turn on till I connect it to power supply (However battery is charged 50%+).

Then my system takes much time than usual and boot up to a screen where it is written "CMOS Checksum is invalid" Eroor 502.

I have opened it to replace the CMOS battery but end up finding nothing.

I am not in favour of Updating BIOS, because any error will lead me to a Bricked Motherboard.

[Raj_05]

Hi @GraphicCard485,

Welcome to HP Support Community.

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

The "CMOS Checksum Error" typically indicates that the CMOS settings in your laptop have become corrupted or lost, often due to a failing CMOS battery or incorrect BIOS settings. Here are a few steps you can try to resolve this issue without updating the BIOS.

• Replace the CMOS Battery: Even if you couldn't find it initially, most laptops have a CMOS battery somewhere on the motherboard. It might be smaller and harder to locate. Sometimes it's underneath the keyboard or near the RAM slots. Look for a round, silver battery about the size of a coin. If you replace it, ensure it's the same type (often CR2032).
• Reset BIOS Settings: If you can access the BIOS setup utility (usually by pressing a key like Esc, F2, F10, or Delete right after powering on), you can try resetting the BIOS to its default settings. Look for an option like "Load Setup Defaults" or "Reset BIOS Settings."
• Check for Loose Connections: Sometimes, reseating the CMOS battery or checking for loose connections (especially if you've recently opened the laptop) can resolve the issue.

Updating the BIOS is typically a safe procedure if done correctly, but it's understandable to be cautious. However, sometimes it's necessary to resolve certain hardware issues. If you decide to go this route, ensure you follow the HP instructions precisely and use a reliable power source to avoid interruptions during the update process.

I hope this helps.

Take care and have a good day.

Please click “Accepted Solution” if you feel my post solved your issue, it will help others find the solution. Click the “Kudos/Thumbs Up" on the bottom right to say “Thanks” for helping!

Alden4

HP Support 

[GraphicCard485]

I've update my BIOS to recent update but still the problem persist. Also tried to locate the CMOS battery but I'm unable to find it. I had 2 query that

I have shifted from Hard Drive to SSD, and set my boot with SSD, so retting the bios setting, will it affect the boot time? 

and If I continue to use my system as it is, will it affect the Motherboard?

[Raj_05]

Hi @GraphicCard485,

Thank you for your response, 

Here are the answers to your queries and some suggestions to address the problem.

1. Effect of Resetting BIOS Settings on Boot Time:
   • Resetting BIOS Settings: Resetting the BIOS settings to default should not affect the boot time significantly if your SSD is properly configured as the primary boot device. However, you may need to reconfigure certain settings such as boot order, SATA mode (AHCI/IDE), and any overclocking or custom settings you had previously set up.
2. Impact on Motherboard:
   • Using the System with a CMOS Checksum Error: Continuing to use your system with a CMOS checksum error won't immediately harm your motherboard, but it can lead to stability issues, incorrect system time, and loss of BIOS settings. It's generally a good idea to resolve the CMOS issue to avoid potential problems.

I hope this helps.

Take care and have a good day.

Please click “Accepted Solution” if you feel my post solved your issue, it will help others find the solution. Click the “Kudos/Thumbs Up" on the bottom right to say “Thanks” for helping!

Alden4

HP Support 

[GraphicCard485 · Accepted solution]

Hey, I've changed my Internal Battery on Jul 05 2024, and in last 24 hours I haven't countered any CMOS Checksum Error. I think there was some issue with Battery, providing power to CMOS. 

[Raj_05]

Hi @GraphicCard485,

Thank you for your response, 

Is there anything else that I can help you with today?

Please click “Accepted Solution” if you feel my post solved your issue, it will help others find the solution. Click the “Kudos/Thumbs Up" on the bottom right to say “Thanks” for helping!

Take care and have a great day ahead!

Alden4

HP Support 

[GraphicCard485]

No.