No CMOS battery

Took my Vista offline Christmas week to mess around with 8.1 computer. Decided this morning I'd had enough of 8.1 for awhile so I was switching all the power and cables back over and wouldn't you know -Vista wouldn't boot! Did the regular stuff. Unplug things one at a time. All it would do was flash the power lite for 1 second then nothing. It's dusty but it was this dusty last week? Unplugged extra drives, then unplugged main drive, disconnected the monitor, took out the ram, pulled the plug on fans, usb - everything. Resetted the main board power. You name it. I tried it. Well last straw - I pulled the CMOS battery out with everything now back in or so I thought. For some curious reason I push the power botton an guess what- It Powered Up! Turned it off connected the video to see if it would tell me to fix cmos or something but no. It screened - "The System fan has failed. Fix to prevent damage to your computer. Press F2 to continue." So I continue and here I am running with the cmos battery sitting in front of me on my desk! And one fan is still disconnected so it caught my error of not plugging everything back. I have the same battery for my multimeter in my work truck so no big deal. But I never knew you could boot without the battery. A new troubleshooting step I'll remember for sure!

 

CMOS is to keep configurations if computer is unplugged and to keep the clock up to date.
As you discovered, if a desktop computer is plugged in or a laptop is running off a battery, it doesn't require a CMOS battery to power up.

 

I unplugged it 15 times during the process. I even swap recptacles to eliminate the electrical part? That's what suprised me also the fact that the battery wasn't in at the final try.?

 

Newer computers store BIOS settings in non-volatile memory that doesn’t need a battery. The battery is only needed for the real time clock.

Here's an article that will explain everything you need to know about the CMOS battery.

http://www.makeuseof.com/tag/why-does-my-motherboard-have-a-battery/

 

When you perform a hard BIOS reset, the unit is unplugged from AC, a laptop has it's battery pulled, and then the CR2032 is pulled.

This resets everything back to OOB (out of the box) and often does get you booted and running. Many modern boards also have removable PROMs which you can flash via another computer. I've also had the occasion to build a "Franken-PC" with a Core2Quad which did not boot until I flashed the board via CD-ROM.

Ahhhhh, the fun we have...

:-D

 

I'll go read that article and a couple others now that I've seen this. With a good battery installed it screened the bios on first boot then went on to vista. Everything works extra disks cd external toshiba drive -all. Date on screen and in event viewer was rolled back to 1-1-2009 @1200. Battery read 3.05 out of 3.2 but could have been failing under even a light load? Another learning experience! Thanks all! And Happy New Year!

 

Eldon- Your link had a link to this page which has several links to topics and pdf's. Some for me a refresher and some new info. Futher links there also for interrupt tables, dma's and plug and play and other topics. Some frown on wiki's but some of it is good.

http://en.wikipedia.org/wiki/BIOS

 

Thanks Imandy Mann.

That's a lot of Info!