Cmos checksum is invalid. 502 error in hp pavillion gamingec1052 ax

[Imranshah02]

Please help. System showing only black screen.

[Gaya1239]

Hi @Imranshah02,

Welcome to The HP Support Community.  

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

I understand you are getting the CMOS Checksum Invalid 502 error, which indicates a problem with the system's CMOS (Complementary Metal-Oxide Semiconductor) settings, usually caused by issues like:

1. Corrupted BIOS settings
2. A failed CMOS battery
3. An interrupted or failed BIOS update

Here’s a step-by-step guide to troubleshoot and resolve the issue:

1. Perform a Hard Reset

1. Turn off the laptop.
2. Disconnect the power adapter and remove any external devices.
3. Press and hold the power button for 15 seconds to drain residual power.
4. Reconnect the power adapter and turn on the system.

2. Reset the BIOS

1. Turn off the laptop.
2. Press the Esc key repeatedly while turning it back on to enter the Startup Menu.
3. Select F10 for BIOS Setup.
4. In the BIOS menu:
   • Select the option to Load Setup Defaults (usually under the "Exit" or "Main" tab).
   • Save and exit the BIOS by selecting Save Changes and Exit.

3. Update the BIOS

If the system boots, check for a BIOS update:

1. Visit the HP Drivers and Software page.
2. Search for your laptop model (HP Pavilion Gaming - 15-ec1052ax).
3. Download and install the latest BIOS update.

4. Replace the CMOS Battery (if needed)

A dead CMOS battery can cause this error. To check:

1. Access the battery by removing the back panel (refer to the service manual for your laptop model).
2. Replace the CMOS battery with a new one (CR2032 is the most common type).
3. Reassemble the laptop and turn it on.

5. Recover the BIOS

If the above steps fail:

1. Turn off the laptop and ensure it's connected to power.
2. Hold the Windows + B keys and press the Power button for 2-3 seconds, then release the Power button while still holding the keys.
3. If the BIOS recovery screen appears, follow the instructions to recover or reinstall the BIOS.

Refer to this document: HP Pavilion Gaming - 15-ec1052ax User manual

HP PCs - 500, 501, or 502 error displays on a black screen
 

I hope this helps. 

Take care and have a good day.

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