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Does this all-in-one have a CMOS battery? Support says no... Having checksum invalid/CMOS problem.

HP Recommended
20-c410 all-in-one
Microsoft Windows 10 (64-bit)

20-c410 all-in-one will not boot. I have done the Windows key/B key reload but it does not solve the issue. PC  is stuck in the same loop. Wondered if replacing the CMOs battery might help, but HP support says there is no such battery in this machine. 

The endless loop:

     Bios info (version, etc.) flashes on screen.

     Next screen says “ manufacturers programming mode is in unlock mode”

     Final screen says “ CMOS checksum is invalid. ...................CMOs reset 502” 

and the loop begins again.  

Tapping escape, f9, f10, f11 all do nothing. There is an onscreen keyboard under the checksum message - keyboard appears to do nothing.


IF there IS a CMOS battery, might changing it help?  Any other ideas....

Thank you for any help!         Kathy

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Message 2 of 2
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HP Recommended

Hopefully one of these documents will cover (and solve) your problem...

Turn off the computer, and then connect the power cord.
Press and hold the Windows key and the B key at the same time, and then press and hold the power button for 2 to 3 seconds.
Release the Power button but continue pressing the Windows and B keys. You might hear a series of beeps.
The HP BIOS Update screen displays and the recovery begins automatically. Follow any on-screen prompts to continue the startup to complete the recovery.
HP BIOS Update recovery in progress

If the HP BIOS Update screen does not display, repeat the previous steps but press the Windows key and the V key. If the screen still does not display, your computer might not support the feature or there is a hard drive issue. Continue to the next step to install a BIOS recovery file from the HP website.
If the Power light turns off, the Power button was held too long. Repeat the previous steps, making sure to hold the button for only 2 to 3 seconds.

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