laptop won't power on, power button is flashing.

[SeleneTawny]

Every day my laptop won't power up and the power button is flashing. I unplug and discharge the battery, plug in and press power button. As it is starting up I get a warning that the CMOS checksum is invalid, error 501. I have updated the bios and ran all of the diagnostics from HP Support Assistant with no errors.

[Max3Aj]

@SeleneTawny, Welcome to HP Support Community. 

Thank you for posting your query, I will be glad to help you. 
I understand how frustrating it can be when your HP Envy x360 won’t power on and shows a flashing power button along with a CMOS Checksum Error and Error (501). You've already done a great job updating the BIOS and running diagnostics, that’s a solid first step.

Let’s go through a few more steps to help resolve this issue:

Perform a Hard Reset

This helps clear any residual electrical charge that might be causing the issue.

• Disconnect the AC adapter.
• Press and hold the power button for 15 seconds.
• Reconnect the AC adapter (do not connect any peripherals yet).
• Try powering on the laptop.

Reset the BIOS Defaults

Since you're seeing a CMOS checksum error, resetting the BIOS to factory defaults can help.

• Turn on the laptop and immediately press the F10 key repeatedly to enter BIOS Setup.
• Once in BIOS, press F9 to load defaults.
• Press F10 to save and exit.

Replace the CMOS Battery (if issue persists)

The CMOS battery may be failing, especially if the error appears frequently. Unfortunately, in many modern laptops like the Envy x360, the CMOS battery is not easily user-replaceable and may require professional servicing.

Run HP UEFI Hardware Diagnostics (Outside Windows)

To rule out hardware issues:

• Turn off the laptop.
• Press the power button, then immediately press Esc repeatedly until the Startup Menu appears.
• Press F2 to open System Diagnostics.
• Run the System Test and Component Tests (especially for memory and motherboard).

If the CMOS error continues even after these steps, it may indicate a deeper issue with the system board or CMOS circuitry. In that case, we suggest you please visit the nearest HP authorized service center, the service team will check and assist you. 
Kindly follow this link to locate the nearest HP service center: HP® Service Center Locator - United States | HP® Support
(Select the country from the dropdown menu and enter the city name or pincode) 
 

I hope this helps. 

Take care and have a good day. 

Please click “Accepted Solution” if you feel my post solved your issue, it will help others find the solution. Select "Yes" on the bottom left to say “Thanks” for helping! 

Max3Aj

HP Support