CMOS checksum error and BIOS update

[idunnonuthin]

When I turn on the laptop after it has been disconnected from mains power (it does not have a battery) I get a screen message informing me that the CMOS checksum is invalid (error 502), and a reboot is required to reset it to the default configuration. The reboot does enable access to Windows 10 and all appears to work as expected, but the system clock restarts at the date and time at which the laptop was previously disconnected from mains power. This does not happen if the laptop is either restarted or shut down but left connected to mains power...only when the mains power is turned off or the power cable is disconnected. I have not attempted to remove or replace the CMOS/RTC battery, as- not being tech savvy- I am reluctant to take apart the laptop. Also, I am not sure replacing the CMOS battery will resolve the issue, because I have not been able to update the BIOS or change the data in the existing BIOS.

I have tried 3 times to update the BIOS via the HP website, but the process failed each time. I attempted to access the BIOS at start-up, but access is protected by a password which I do not have. Apparently the laptop was originally part of a business network...I do not know what business and so I have no way of obtaining a password.

Based on the above facts, is it reasonable to assume that:

• the CMOS battery is the problem and should be replaced?

• the BIOS cannot be updated- or settings changed- because the laptop is still being recognised as part of a business network, and therefore requires a password to enable any update or change?

If I replace the CMOS battery, will that eliminate both the CMOS checksum error and the date and time error, or will those issues persist because the BIOS information has been reset to a default configuration...which I am unable to change or update?

All helpful thoughts and suggestions will be appreciated.

[ub6424]

Hello @idunnonuthin 

Sorry to hear that you are having problems ... I would like to help you.

(1) Replace RTC battery ( CR2032 3V )

--->>> HP ProBook 430 G1 Notebook PC Maintenance and Service Guide

Page 55 Component replacement procedures

(2) Ploblem should be fixed

Kind regards