161 Real Time clock power loss

[robwild]

Hi, yesterday, for the first time (ever) I got a 161 Real Time Clock Power loss error message, clock defaulted to 1/1/2004 on reboot, so I reset the time. It has run OK today, but I've not shut down yet.

I've done a bit of googling / forum searches etc and I'm assuming that it is a CMOS battery issue, but I have not yet purchased a replacement, as I'm not sure what type to buy, (not opened up the case to look yet), please advise.

Also on p. 269 of the HP Maintenance & Service quide for this model, it says "Before replacing the battery, it is important to back up the computer CMOS settings." but it does not say how to do this. Please advise, does HP have a utility to do this?

On another post (for a notebook) it recommended doing the change in safe mode, I'd assumed that I'd have to power down first, please advise.

If you power down how long do you have before power drains away and the settings are lost?

Apologies for my ignorance but in umpteen years of computing  on a variety of computers I've never changed a CMOS battery, it looks like I've got away with it to date.

Please advise of the best method of resolving this issue. 

Thanks

[Big_Dave]

Hi,

Taking note or backing up the CMOS settings means that if you made changes to the default settings then you need to make note of those changes or the BIOS default settings will be used. Some BIOS functions will allow you to replicate the settings to external media so that the settings can be restored after a CMOS clearing or when the BIOS has been flashed (updated).  If the CMOS battery is in fact dead and you have subsequently booted up your PC then you are you are using the default settings.

The standard CMOS battery that has been used for years in many PCs is the CR2032.  Sometimes this battery is called the Real Time Clock battery.  The typical large chain drug stores carry the CR2032.

You don't need to be in safe mode to change the battery.  However, I suggest that you power down the PC, unplug it from the wall and then hold down the power button for 60 seconds.

Here is a HP Video on how to change the CMOS battery.

Depending on the motherboard in your PC, the CMOS battery may be mounted vertically rather than the typical horizontal flat position.

[robwild]

Thanks for the reply Dave, particularly the link to the HP video; it looks staightforward. I have some CR2032s in stock, so hopefully they will suffice. I've not knowingly altered the BIOS settings, but I will look at them first.