the cmos jumper is inserted on 2 pins on the board, but actually there are 3 pins there. a friend told me that if there is a problem the board shuts down untill you remove the jumper and fix it on the other two. is it through
This is correct. This is one of the methods of clearing your BIOS and resetting it. Many times this method is used when the BIOS data becomes scrambled.
Simply power off your machine, and then remove the jumper from pin #1 & #2 and place it on pin #2 & #3. Leave the jumper in pin #2 & #3 for about 20 to 30 seconds then return it to the original two pins. Power the machine back up and you now have a fresh BIOS.
Back when overclocking started to get really popular, many users would use this method to reset there BIOS after an overclock change failed. One of the really popular boards for overclocking the AMD processors (Intel chips were locked back then) was the MSI and Epox boards, among others.
Here's another trick that might come in useful someday. If you're working with an older motherboard that doesn't have the jumper and want to clear the BIOS, try this. Find the CMOS battery and take it out. Get some thin silver foil or foil coated paper, screw it up into a suitable wad and put it into the battery holder where the battery was making sure you bridge the contacts. Leave for 30 minutes. Then remove the foil, replace the battery and give it a try. This has got me out of a tight spot a couple of times over the years.
I had almost an opposite scenario once, for BIOS getting reset undeliberately. Where a friend of mine working as a doctor/physician in his clinic had to call an IT guy to replace the batteries every 6 months or so. He had some medical hardware connected to his PC. The drained batteries caused his BIOS setup to reset which for some reason left his medical hardware unfunctional. His only resolution was to replace the batteries and reconfigure BIOS. The guy was so frustrated about this. Then I told him to keep the power socket ON even after he shuts down. He didn't pay attention at first, at our next meeting he started the story again were I insisted on him to keep the wall power ON even after the PC is OFF. Few months latter he was so happy that he never needed to replace batteries again!!
I wasn't sure, just guessing that the DC current generated by the power supply while the machine was OFF would keep up the BIOS setting. Seams so....!! :o
What remains a mystery to me is how did the lithium batteries give up just after few months :?