Clearing CMOS memory - What did I fix?

bert8for3 · 03-09-10, 08:06 AM

I'd sure be curious to know what it was I "fixed" last night on my pc.

I pressed the start button to boot up, and nothing happened. Then I noticed that the system was starting to whir up (fans), but only for a second or two, then going dead, and repeating this over and over.
I fiddled with the switch in case it wasn't making proper contact, tried again, same thing.

Then I noticed from the POST display on the m/b that it was showing complete power off. Some thumbing through the m/b manual and a reboot and looking at the POST display showed that the system wasn't completing the POST and was going to power off.

After sweating a bit and thumbing the manual some more, I figured that the thing to do (being the only thing I could think of) would be to clear the CMOS memory, which I did with some trepidation. Then everthing was fine. I had to reset system date/clock in bios, but no big deal.

I haven't a clue though what caused this. Any ideas?

AVGWarhawk · 03-09-10, 10:50 AM

Not sure either. I have pulled the CMOS battery a few times as well to get a computer to fire up. Mostly laptops. I would say to you though that the desktop I had to keep pulling the CMOS to get it run had another problem. It would not run sometimes and when it did it would show Windows is shutting down after a few hours of use yet I did not ask to shut down. I was getting what you were after that...just the fans going for a few seconds then nothing after the power button was pushed. I would pull the CMOS and then it would fire up again (sometimes). I finally found it was the power button. I went and got a new case with power button. Been running about 2 years no without issue.

bert8for3 · 03-10-10, 08:00 AM

Quote:

Originally Posted by AVGWarhawk

Not sure either. I have pulled the CMOS battery a few times as well to get a computer to fire up. Mostly laptops. I would say to you though that the desktop I had to keep pulling the CMOS to get it run had another problem. It would not run sometimes and when it did it would show Windows is shutting down after a few hours of use yet I did not ask to shut down. I was getting what you were after that...just the fans going for a few seconds then nothing after the power button was pushed. I would pull the CMOS and then it would fire up again (sometimes). I finally found it was the power button. I went and got a new case with power button. Been running about 2 years no without issue.

Strange. By the sound of it, your problem was worse than mine. And whatever mine was, it hasn't happened again

AVGWarhawk · 03-10-10, 11:36 AM

Mine was weird. I would use the computer for a few days without issue then all of a sudden the blue screen pops up showing 'Windows is Closing.' Just like I had pressed Start and shut down the computer. Sometimes it would fire up again without a problem. Sometimes just the fans would spin and then nothing. I would pull the battery and then it would fire up most times. The computer behavior got more frequent with the shutting down like I asked it to shut down. I did the usual. Virus scan, etc. I had an extra PSU and that did not cure the issue. Finally, I had an extra on/off button from a old case. I attached the wires and sha-zam...she fire right up and ran for a week straight without shutting down by itself. I went and purchased a new case with button. Been running ever since. What threw me for a loop was pulling the CMOS did infact allow the computer to fire up most times. I did learn through this experience that the CMOS battery can infact be part of getting a computer to start again.

Reece · 03-10-10, 06:46 PM

Seems that the CMOS was corrupted for some reason, I wouldn't like that since it will be a worry now for awhile every time you turn your computer on!!

But it could be anything from CPU, RAM , motherboard, one of the cards!! you will just have to keep fingers crossed for awhile, maybe a spike in the mains!

Arclight · 03-11-10, 01:24 AM

Did you do any overclocking? My board will do that if it can't start because I tweaked it a little to hard (memory timings for example). After 2 failed attempts it automatically restores backup BIOS, but if your board doesn't have that it will just keep failing and powering off.

Resetting BIOS just reverts all settings to factory default; check all of them to make sure it's still properly set up.

jumpy · 03-11-10, 03:02 AM

Could it be possible that your mobo battery is on the way out?

I had to replace mine recently following 'ntldr missing' error during bootup - the bios was reset to default, so didn't know which drive to boot windows from.
You could reset it in the bios then load windows, but the next time you switched off it would revert back to default. Lost time and date too which made my all programs list on the start menu think it had all new applications highlighted

bert8for3 · 03-11-10, 01:43 PM

Could be the battery I suppose; still, for mine whatever it was it's still working ok.

03-09-10, 08:06 AM	#1
bert8for3 Ace of the Deep Join Date: Dec 2005 Location: Canada Posts: 1,124 Downloads: 110 Uploads: 0	Clearing CMOS memory - What did I fix? I'd sure be curious to know what it was I "fixed" last night on my pc. I pressed the start button to boot up, and nothing happened. Then I noticed that the system was starting to whir up (fans), but only for a second or two, then going dead, and repeating this over and over. I fiddled with the switch in case it wasn't making proper contact, tried again, same thing. Then I noticed from the POST display on the m/b that it was showing complete power off. Some thumbing through the m/b manual and a reboot and looking at the POST display showed that the system wasn't completing the POST and was going to power off. After sweating a bit and thumbing the manual some more, I figured that the thing to do (being the only thing I could think of) would be to clear the CMOS memory, which I did with some trepidation. Then everthing was fine. I had to reset system date/clock in bios, but no big deal. I haven't a clue though what caused this. Any ideas? __________________

03-09-10, 10:50 AM	#2
AVGWarhawk Lucky Jack Join Date: Jun 2005 Location: In a 1954 Buick. Posts: 28,253 Downloads: 90 Uploads: 0	Not sure either. I have pulled the CMOS battery a few times as well to get a computer to fire up. Mostly laptops. I would say to you though that the desktop I had to keep pulling the CMOS to get it run had another problem. It would not run sometimes and when it did it would show Windows is shutting down after a few hours of use yet I did not ask to shut down. I was getting what you were after that...just the fans going for a few seconds then nothing after the power button was pushed. I would pull the CMOS and then it would fire up again (sometimes). I finally found it was the power button. I went and got a new case with power button. Been running about 2 years no without issue. __________________ “You're painfully alive in a drugged and dying culture.” ― Richard Yates, Revolutionary Road

03-10-10, 11:36 AM	#4
AVGWarhawk Lucky Jack Join Date: Jun 2005 Location: In a 1954 Buick. Posts: 28,253 Downloads: 90 Uploads: 0	Mine was weird. I would use the computer for a few days without issue then all of a sudden the blue screen pops up showing 'Windows is Closing.' Just like I had pressed Start and shut down the computer. Sometimes it would fire up again without a problem. Sometimes just the fans would spin and then nothing. I would pull the battery and then it would fire up most times. The computer behavior got more frequent with the shutting down like I asked it to shut down. I did the usual. Virus scan, etc. I had an extra PSU and that did not cure the issue. Finally, I had an extra on/off button from a old case. I attached the wires and sha-zam...she fire right up and ran for a week straight without shutting down by itself. I went and purchased a new case with button. Been running ever since. What threw me for a loop was pulling the CMOS did infact allow the computer to fire up most times. I did learn through this experience that the CMOS battery can infact be part of getting a computer to start again. __________________ “You're painfully alive in a drugged and dying culture.” ― Richard Yates, Revolutionary Road

03-10-10, 06:46 PM	#5
Reece CINC Pacific Fleet Join Date: Sep 2003 Location: Down Under Posts: 34,688 Downloads: 171 Uploads: 0	Seems that the CMOS was corrupted for some reason, I wouldn't like that since it will be a worry now for awhile every time you turn your computer on!! But it could be anything from CPU, RAM , motherboard, one of the cards!! you will just have to keep fingers crossed for awhile, maybe a spike in the mains! __________________ *Sub captains go down with their ship!*

03-11-10, 01:24 AM	#6
Arclight Navy Seal Join Date: Jun 2008 Location: Land of windmills, tulips, wooden shoes and cheese. Lots of cheese. Posts: 8,467 Downloads: 53 Uploads: 10	Did you do any overclocking? My board will do that if it can't start because I tweaked it a little to hard (memory timings for example). After 2 failed attempts it automatically restores backup BIOS, but if your board doesn't have that it will just keep failing and powering off. Resetting BIOS just reverts all settings to factory default; check all of them to make sure it's still properly set up. __________________ Contritium praecedit superbia.

03-11-10, 03:02 AM	#7
jumpy Admiral Join Date: May 2003 Location: Midlands, UK Posts: 2,139 Downloads: 22 Uploads: 0	Could it be possible that your mobo battery is on the way out? I had to replace mine recently following 'ntldr missing' error during bootup - the bios was reset to default, so didn't know which drive to boot windows from. You could reset it in the bios then load windows, but the next time you switched off it would revert back to default. Lost time and date too which made my all programs list on the start menu think it had all new applications highlighted __________________ when you’ve been so long in the desert, any water, no matter how brackish, looks like life

03-11-10, 01:43 PM	#8
bert8for3 Ace of the Deep Join Date: Dec 2005 Location: Canada Posts: 1,124 Downloads: 110 Uploads: 0	Could be the battery I suppose; still, for mine whatever it was it's still working ok. __________________