Laptop won’t wake from sleep + shows 502 CMOS error + Secure Boot update error in Event Viewer

[Amogh9000]

Whenever I put my HP laptop to sleep, it sometimes refuses to wake up when I open the lid or press any key. The keyboard and power button become completely unresponsive, and I have to force shutdown by holding the power button.

After turning it back on, I get a “502 BIOS Error” on boot.

When I checked the Event Viewer, I also noticed this message:

“The Secure Boot update failed to update a Secure Boot variable with error Unknown HResult Error code: 0x800700c1.”

The entry also mentions:

FirmwareManufacturer: Insyde
FirmwareVersion: F.29
OEMManufacturerName: HP
OSArchitecture: amd64

I haven’t updated to Windows 11 25H2 yet — I’m still on 24H2, since I heard about issues in the new version.

I just want to confirm:

• Is this BIOS/firmware related or a Windows issue?

• Should I avoid using Sleep mode for now?

• Is there any fix or update available to stop this from happening?

[Kuroi_Kenshi]

Hi @Amogh9000,

Welcome to the HP Support Community! We're stoked to have you on board! 

To help us get started on resolving your issue, could you please share the model name of your device?

We're looking forward to helping you get back up and running! 

Best regards,

[Amogh9000]

Its a  OMEN by HP Gaming Laptop 16-xd0xxx

[Amogh9000]

Also as far as I have observed when the laptop is in sleep for a long time(>1hr) the above mentioned problem occurs
If it is sleep for 30-40mins around , the error doesnt happen.

[Kuroi_Kenshi · Accepted solution]

 Hi @Amogh9000,

I understand your OMEN 16‑xd0xxx laptop sometimes won’t wake from sleep and shows a 502 BIOS/CMOS error, along with the Secure Boot update failure in Event Viewer. Let’s go through a few points to clarify what’s happening and steps you can take.

Understand the 502 BIOS/CMOS error
This error usually appears when the system clock or CMOS settings fail to initialize correctly.
It often points to a firmware-level issue rather than Windows itself.

Secure Boot update error explanation
The Event Viewer entry about “Secure Boot update failed” indicates that the system attempted to update a Secure Boot variable in the BIOS but didn’t succeed.
This can happen if the firmware is not fully compatible with certain sleep/hibernate transitions.

Relation to Windows vs BIOS/Firmware
Since you are still on Windows 11 24H2 and the issue occurs after extended sleep (>1 hour), this points to a BIOS/firmware behavior rather than a Windows OS bug.
Shorter sleep sessions don’t trigger the issue, supporting this conclusion.

Avoid using extended Sleep mode
For now, yes — avoid leaving the laptop in Sleep for long periods (>30–40 minutes).
Alternatively, use Hibernate or shut down completely if you won’t be using it for a while.

Check for BIOS/Firmware updates
Your system is running F.29.
Check HP’s support page for the OMEN 16‑xd0xxx to see if there’s a newer BIOS that addresses sleep, Secure Boot, or CMOS stability issues.

Power reset and BIOS defaults
If the error persists, try a power reset:

Turn off the laptop, unplug all peripherals, and hold the power button for 30 seconds.

Restart and enter BIOS → Load Setup Defaults → Save and Exit.
This can clear CMOS inconsistencies.

I hope this helps.

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Best regards,