Top Student
Posts: 2
Member Since: ‎08-07-2011
Message 1 of 3 (1,587 Views)
Accepted Solution

dc7600 PC CMOS not remembering settings after battery failure

Re: dc7600 Convertible Minitower, 3GB of RAM, an 80GB HDD and what looks like a 365W PSU.


This PC was not used for several months, and was not plugged into the mains power over the time it was unused. When

I started it again recently, it started up automatically, without my pressing the power button. Rather than running

normally, before booting in to Windows, it had a cursor at the top left of a black screen, and counted through what

I'm guessing is the RAM MB, as it stopped counting when it got to roughly 3000MB. Two error messages then appeared,

the first advising that the system config had been changed since last boot, or loss of power to the real time

battery had occurred, and the battery might not be functioning properly and may need replacement. I had to press F1

to continue.


The second message began with the number 163 and advised that the time and date were not set, possibly due to loss

of onboard battery power and again saying the battery may need replacement.  I again pressed F1 to accept this, 

and then it booted and ran normally, enabling me to reset the time and date.


To try to fix the above problem, I have:

- installed a new CMOS battery (twice, in case the first new one was dodgy)
- reset the BIOS to factory default settings (twice), using the F10 BIOS settings, as I can't see a jumper switch

on the main board.


When I leave the PC plugged in to the mains with the power on, after having been closed down (correctly) it will

boot happily and run normally with no problems when the power button is pressed.  However, if I close the PC down

and unplug it from the mains, when I try to reboot it, it always goes through the RAM counting, error message and

date checking/resetting process again. The PC runs perfectly after this sequence of events.


So far, the problem persists.  It's obviously not an HDD or OS error, so are there any other things that can be done

to sort out the problem, e.g.. flashing the BIOS, or am I looking at replacing the motherboard? 

Any help you can give me would be appreciated.





I don't leave the PC plugged in to the mains power supply, due to the fact that the power supply in my area is

subject to spikes, brown outs and electrical storms.

Posts: 47,948
Member Since: ‎07-13-2010
Message 2 of 3 (1,582 Views)

Re: dc7600 PC CMOS not remembering settings after battery failure



Unplug everything from the PC.  Power, monitor cable, keyboard and mouse cable, printer, USB...--everything.


Remove the CMOS battery and carefully check the contacts to make sure they are not corroded and that they are making contact with the battery. Clean/adjust the contacts as necessary.


Then, press and hold the little yellow button (Clear CMOS) near the battery for 30 seconds. Put everything back together. You will have to reset the BIOS, and hopefully it will be fixed.


If not, probably the motherboard is bad.  Connection from the battery holder to the motherboard is bad.



Top Student
Posts: 2
Member Since: ‎08-07-2011
Message 3 of 3 (1,571 Views)

Re: dc7600 PC CMOS not remembering settings after battery failure

Hello Paul


I've tried all of your suggestions, and I'm still getting the same problem, so it looks like my motherboard isn't sensing the battery for some reason. Probably a symptom of living in the tropics - we've just gone through the wettest Wet Season on record.  I'll mark this discussion as complete. And start looking for a replacement motherboard. . . .


Many thanks for your help, and for taking the time to respond to me!





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