CMOS Checksum is invalid ERROR-502 and battery is not charging

[Jerry04]

Hello Folks and HP community feels glad that i have you by my side to help me.

I'm Facing issue in my laptop since couple of weeks. When I Turn on my Laptop I face issue of CMOS checksum error in BIOS. Also my battery is not giving backup after this issue just in 1.5 year.  Also facing white spot light near charging port even if my laptop is at 0%. I even tried hardware work by plug off battery and resetting CMOS by pressing start button nearby 20 seconds. Also I checked that if battery is blown or not but it is normal. Some of saying that it's issue in BMS (Battery Management System). So community please help me out I'm afraid of this issue and stopped working on that. 

I Hope that I'll Soon Receive better solution.  

[Raj_05]

Hi @Jerry04,

Welcome to HP Support Community.  

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

The "CMOS Checksum is invalid" error (Error 502) usually indicates a problem with the computer's BIOS settings or the CMOS battery. The CMOS battery is a small battery on the motherboard that provides power to the CMOS (Complementary Metal-Oxide-Semiconductor) chip, which stores BIOS configuration data.

Here's what you can try to troubleshoot and resolve the issue:

Reset BIOS Settings:

• Turn off the laptop and disconnect it from any power sources.
• Open the laptop's case and locate the CMOS battery on the motherboard. It's usually a small coin-cell battery.
• Carefully remove the CMOS battery and wait for a few minutes before reinserting it.
• Reassemble the laptop and try turning it on.

Replace CMOS Battery:

• If resetting the CMOS battery doesn't solve the issue, the battery itself might be faulty. Consider replacing it with a new one. You can find replacement batteries online or at electronics stores.

Update BIOS:

• If the CMOS checksum error persists, updating the BIOS might help. Go to the laptop manufacturer's website and search for BIOS updates for your specific laptop model.
• Follow the manufacturer's instructions to download and install the BIOS update. Make sure to follow the steps carefully to avoid any potential issues.

Regarding the battery not charging issue, here are some steps to address that:

Check Power Adapter and Cord:

• Make sure the power adapter is functioning properly. Sometimes, faulty adapters or cords can prevent the battery from charging.
• Try using a different power adapter and cord to see if the battery starts charging.

Battery Reset:

• Some laptops have a battery reset feature. This involves fully discharging the battery and then charging it again. Check your laptop's manual or the manufacturer's website for instructions on how to perform a battery reset.

Battery Calibration:

• If the battery percentage displayed is inaccurate, calibrating the battery might help. Completely discharge the battery, then fully charge it without interruption.

Device Manager:

• Sometimes, issues with battery charging can be resolved by uninstalling and reinstalling the battery driver in 
• the Device Manager.

BIOS Update:

• As mentioned earlier, updating the BIOS can sometimes resolve hardware-related issues, including battery charging problems.

I hope this helps. 
 

Take care and have a good day.

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Alden4
HP Support 

[Jerry04]

The percentage is not increasing and also laptop don't give backup after removing charger. From turning on laptop I see white light even if battery is not fully charged!!!

[Raj_05]

Hi @Jerry04,

Thank you for your response,

Due to limited support, I would request you contact our HP Support and our Support Engineers should be able to sort this out. HP Support can be reached by clicking on the following link.

https://www.hp.com/contacthp/

Please feel free to contact us here anytime you need any further assistance.

Have a great day!

Alden4
HP Support