msg on boot : The Chos checksua is invalid. The Chos will be reset to ...

[Haitham4Soft]

Help in solving this problem, please.
The laptop suddenly shuts down (when it is running on battery only), and when I try to turn it on again, it takes longer than usual for the data to start appearing on the screen, and it shows this message 

( The CHOS checksum is inva I id. The CMOS will be reset to the default conf iguration and will be reboo ted. Please check your BIOS Setup options to see if they change.
CMOS Reset (502) )

What I understood from the message is that the problem is with the small BIOS battery, like a coin cell... I opened the laptop to change it, but I couldn't find it at all on the laptop's motherboard.
The laptop's battery is in very good condition and lasts for about two and a half hours, which has been its normal duration for a long time.
Laptop model: HP Pavilion - 15-cs0006nx

I hope for help , thank you.

[Raj_05]

Hi @Haitham4Soft,

Welcome to HP Support Community.

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

The error message you're encountering, "The CMOS checksum is invalid," typically indicates an issue with the CMOS (Complementary Metal-Oxide-Semiconductor) battery or a problem with the BIOS settings on your laptop. The CMOS battery is responsible for maintaining your BIOS settings, including the system clock and other critical system information, even when the laptop is powered off. When this battery fails or is depleted, you might see errors like the one you're experiencing.

Check for a CMOS Battery:

• On some laptops, particularly more modern or slim models, the CMOS battery might not be a replaceable coin-cell battery like the ones found in desktops or older laptops. Instead, it may be integrated into the motherboard or use a rechargeable capacitor. If the battery is integrated, it might not be easily replaceable by the user.
• If you couldn't find the CMOS battery, it might be embedded within the motherboard, or your model might use an alternative power source to maintain the BIOS settings.

Reset BIOS to Default Settings:

• Sometimes, the BIOS settings might become corrupted, leading to the checksum error. Resetting the BIOS to its default settings might help resolve this issue.
• To do this, follow these steps:
  1. Power on your laptop and immediately start pressing the F10 key repeatedly until the BIOS setup screen appears.
  2. Once in the BIOS setup, look for an option like "Load Default Settings," "Reset to Default," or similar, and select it.
  3. Save the changes and exit the BIOS.

Update or Reflash the BIOS:

• If resetting the BIOS doesn't solve the problem, consider updating or reflashing the BIOS to the latest version. This can sometimes fix issues related to BIOS corruption or compatibility problems.
• Visit the HP Support website and download the latest BIOS update for your specific model.

Test the Laptop on AC Power Only:

• If the problem persists, try running the laptop on AC power without the battery. If the laptop works fine without the battery, it could indicate an issue with the power delivery or the battery itself, despite it appearing to hold a charge.

Inspect the Power Management Settings:

• Since you mentioned the laptop shuts down when running on battery, it's worth checking the power management settings in Windows to ensure there aren't any aggressive power-saving features causing the issue.

Given the symptoms, it seems like the issue might be related to the BIOS settings not being retained, which points to the CMOS battery or an integrated component responsible for maintaining those settings. If you can't locate a CMOS battery, it's best to consider updating the BIOS and checking the power management settings first.

I hope this helps.

Take care and have a good day.

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Alden4

HP Support