Reset CMOS (502)

[Vinz74]

Suddenly, my OMEN, as soon as I turn on the power, starts up by itself, then shuts down, and on the third attempt a message appears on the screen: "Invalid CMOS checksum. The CMOS configuration will be restored and the computer will restart. Afterwards, check the BIOS configuration options to see if they have changed".
After that, it finally boots up. On the desktop, I noticed the date was incorrect, so I thought it might be the CMOS battery on the motherboard. So, after disconnecting everything, I replaced the battery, but the problem persists.
If I leave the power supply connected to the mains without using a surge protector, the problem does not occur, so it seems something is corrupted, especially since I changed the CMOS battery twice thinking it might have been faulty. Any ideas?
Finally, I can say with absolute certainty that the problem started as soon as I installed an operating system update, specifically the "2025-05 Cumulative Update for Windows 11 Version 23H2 for x64-based Systems (KB5058405)" - May 13, 2025
Thanks!

UPDATE (solved): The mystery has been solved. The first time I removed the battery, I must have bent the positive terminal tab, which no longer made good contact. By removing the battery again and bending the positive terminal tab inward, it now fits properly and the problem has disappeared. Thanks to everyone!

[Bill_To]

Greetings @Vinz74 

Welcome to the HP Forum.

You could check CMOS 502 error troubleshooting tips at this HP Site.

But your situation is kind of unusual since your PC eventually will POST and load Windows.

The system date discrepancy would typically be associated with a CMOS battery problem.

It was good to replace the CR2032 MB battery.

I have no thoughts on why a surge protector could be involved. I use a combination of surge protectors and UPS on my PCs and have never seen what you are experiencing.

I have KB5058405 installed on my W11 PCs. No problems.

Uninstall KB5058405 to see what happens.

Computers are complex beasts. It can very difficult to isolate the cause of a specific and unusual problem.

Regards