When the clock starts loosing time, the battery normally is on it's way out. If you get a "checksum" error when booting - it is definately on it's way out. Turn off the computer. Open the case and look to see if there is a round silver battery on the motherboard somewhere. This will be the battery to replace, it will be obvious - lookslike a large watch battery. The replacement number is 2032. Standard battery , can be purchased for 2-3.00 most anywhere. Now if you do not have the round silver battery, it gets a lttle trickier. There were 2 other types. 1. Dallas time clock battery - is a retangular black battery that is either soldered to the board or has pins and is pushed in. It is normally located around one of the outer edges of the board and has the name DALLAS on it. We have never replaced any of these yet, but if it is a push in and can be replaced, you can call an Electronics shop in your area and see if they have them. Be careful pulling it out, gently lift the edges all the way around to loosen it from it's seat. 2. The second most popular is the blue barrel battery. It is normally located near the keyboard connector and it is soldered to the board. On most boards, near (or next to) the battery will be 4 pins in a row with nothing connected to them. This is where you can bypass the onboard battery. You will nee a battery pack that holds 2 either AAA or AA batteries. It may or may not have the connector you need depending on where you buy it. The connector you need has 4 holes in it and slips over top of the 4 pins you located near the battery on the board. It will have only 2 wires coming from it, a black on one end and a red on the other. If you go somewhere like Radio Shack, you will have to buy the pieces seperately and join the wires yourself. If you go to a real electonics store, they may already have it setup the way you need it to be. The battery pack usually has velcro on it so it can be easily attached to the case when you are done. ----- Original Message ----- From: "William Closure" <[log in to unmask]> Sent: Tuesday, December 18, 2001 4:30 PM Subject: replacing motherboard battery > In a message dated 12/17/01 11:31:07 PM Central Standard Time, > > > > > > The battery on the motherboard provides power for two basic > > functions: > > > > 1. Configuration data is stored in RAM (generally CMOS) that *does* > > require a small amount of current to keep its contents. (This is > > "static" RAM, so all it needs is a trickle of power to the memory > > circuitry. "Dynamic" RAM needs somebody to rewrite each and every > > memory location every so often, which makes it cheaper but more power- > > needy.) > > > > 2. There is an electronic clock, similar to the innards of an > > electronic watch (sans display) that keeps track of the time and > > date; as part of the boot sequence, the operating system obtains the > > current time from this circuit and keeps track of time itself while > > up and running. One of the early signs of imminent battery failure > > is that the machine, each time booted, doesn't know what day/time it > > is. > > > > Which brings up the question . . . > > How does one go about replacing the motherboard battery? I have a Magitronic > Pentium, 32 Mg Ram, running Windows 98 of unknown age. The clock has lost 20 > minutes in the last week or so. Should replacement battery be done with > computer running? Plugged in? How do I locate it? How do I know what kind > of battery to use? What do I have to do BEFORE I start messing with this, so > I don't lose up my computer. (I already have one down.) I have memories of > reading about computers blowing up (well, not literally) if batteries were > allowed to die. > > I checked the archive, but couldn't find anything that addresses these > questions at this simplistic level. Any web sites that can educate me? > > William Closure > Visit our website regularly for FAQs, articles, how-to's, tech tips and much more http://freepctech.com