I've been working with computers for years and this is the first I've ever run into this. My dad has an old AT 450 machine. It has run great for years. A few weeks ago he got a nasty virus. I've Fdisk the machine and reinstalled all the software, just the standard stuff, and it is fine, accept it is suddenly running down the CMOS batteries. I have put two in it in a week. This last one I put in yesterday and today it reports low CMOS battery and lost the time.

Anyone run into this before?

thanks in advance.

Yup, Just last week someone brought me a notebook(AMD 433) that would not boot up, and couldn't access the bios. Opened it up and replaced the CMOS battery. Lucky, it was a standard watch battery type. Replaced it and got the bios back. I had to re-install windows since some of the files got corrupted. Working fine now.

I've been working with computers for years and this is the first I've ever run into this. My dad has an old AT 450 machine. It has run great for years. A few weeks ago he got a nasty virus. I've Fdisk the machine and reinstalled all the software, just the standard stuff, and it is fine, accept it is suddenly running down the CMOS batteries. I have put two in it in a week. This last one I put in yesterday and today it reports low CMOS battery and lost the time.

Anyone run into this before?

thanks in advance.

Do you leave the system powered up or turn it off when you're done? The cmos battery is used when the system is turned off to maintain bios settings and keep the computer clock running, etc. Leave the machine on for awhile after you replace the battery. Know how a new cordless phone or cell phone needs to be charged for 24 hours before use? Same principle.

Actually, not the same principle at all for most CMOS batteries. Most, such as the watch type mentioned in the second post, are not rechargeable. They are just standard batteries. Therefore, they do not "charge" when you use them.

- John...

Maybe it's not the battery...seems to me there was a virus out not too long ago that screwed with the CMOS settings including the clock.
Is there possibly a BIOS upgrade that you could flash onto that MB? What brand/mfgr is this MB?

I would suspect a possible motherboard problem, but would need to see the computer to be sure.

Rick,

I expect that Matt is most likely correct, but it depends on a few items.

1. What type of battery are you replacing the old one with?

2. Have you checked the internal five volts when the computer is running?
(I have a reason for asking the qestion above).

3. I expect the old battery was a Lithium, what are the new ones?

4. If you have an ohm-meter, can you measure across the two posts that the new battery hooks up to (with the battery out) and the power off?

5. Have you gone back in and checked the bios to see if it has really changed? Maybe it's not really changing, but you haven't got rid of your virus. Is it possible that the virus is getting reinserted by a disk that you are using or installing from?

Fred.

Actually, not the same principle at all for most CMOS batteries. Most, such as the watch type mentioned in the second post, are not rechargeable. They are just standard batteries. Therefore, they do not "charge" when you use them.

- John...

Cool. Why does a system which is not connected to power seem to lose it's CMOS battery faster than one that is?

I agree with the consensus about the motherboard going bad. However, I just had an experience where I was ready to trash the motherboard after going through 3 batteries myself.

It turned out I had collected all these CMOS batteries in my computer toolkit on ly to realize that they were all no good anymore. I had my buddy buy a new one from Radio Shack and his computer has been running fine for months now.