Like everything else, computers get older. Here at Logical Expressions, we still have an old Pentium that we bought in 1995. Her name is Jessica. Up until recently, Jessica was going strong. Then she started getting sort of odd errors when booting up and shutting down. Contrary to popular belief, yes there are still a lot of things you can do with an older computer, so we were unwilling to let Jessica go to the big digital dumpster in the sky.
We resurrected the oldster by replacing the CMOS battery. Yes, a battery. What a lot of computer users don’t realize is that virtually every computer has a battery inside that lurks on the main system circuit board (generally referred to as the "motherboard"). These batteries last a long time, but not indefinitely.
As you may have noticed, when most older computers boot up, they display messages and go through memory tests. At some point, you might see something like "Press F2 for set up." That setup is generally called the CMOS setup and is where you set up hardware components like a hard disk or floppy disk.
When you turn off your computer, the battery on the motherboard helps retain your CMOS settings, most notably, the fact that the computer has a hard disk. If the battery dies, the computer essentially loses its "mind." (After all, a computer that does not know it has a hard disk cannot access that hard disk.) It is always a good idea to go into the setup and write down the CMOS settings while the battery is healthy and all is well. If you need to replace the battery or it dies, this information is lost, so be sure to write it down first!
In our case, Jessica’s battery was getting weak, which accounted for the odd errors. I e-mailed Micron PC and their tech support replied telling me that the battery could not be replaced. However, we determined that the battery was within a chip, which could be replaced. We found the part number online, pulled the chip off the motherboard, and replaced it with the new one I bought for $15.00.
So Jessica is back up and running better than ever.