If the clock in my computer is not keeping time, is this a sign of the “battery” going? Does this battery control something called the BIOS? If the battery goes, I won’t be able to boot up in the normal fashion, will I? Does the BIOS help the computer remember how to boot-up, and such, when the power is off?
What kind of battery is this, and where would I find it on the inside of the CPU? Also, I understand there’s always risk of static discharge off of me which can damage the chips. What is the best way to ground myself to guard against this?
At a manufacturing site I once worked at, we wore grounding straps on our wrists which then attached to special mats. Yet, people tinker with their computer hardware all the time like it’s nothing (swapping out drives, etc.) Aren’t they worried about the consequences from static discharge?
The battery is usually a little coin-sized lithium cell (bright silver in colour) held down by a little spring clip; replacing it is simple (have a look first and write down the battery type you need; you won’t just be able to go to a store and pick the one that looks right as there are quite a few similar-looking types).
When you work inside your PC, leave it plugged in and switched on at the wall(to maintain the earth connection) but switched off at the front panel of the PC. Touching the metal case of the PC with your hand should be sufficient to discharge any harmful static; I tend to keep one hand on the metal when actually inserting or removing any components.
Some older computers have a small battery connected via wires. Those batteries are usually rectangular plastic things about an inch long, and connected to the motherboard with a single pair of wires.
The battery keeps a memory chip alive; this chip holds the setup information for the computer, such as the type of hard drive, what configuration to use for accessing memory and I/O ports, etc. Before you remove the battery, go to the setup screen and write down all the information. You’ll need to restore these settings after you replace the battery.
In the old days, the most important piece of information was the hard drive configuration - number of heads and cylinders, etc. Unless you get that right you couldn’t access the hard drive at all. These days hard drives are configured automatically. These days motherboards have a lot of built-in functionality (audio, I/O ports, etc.) so these settings are important.
Your clock not keeping time can be a sign of the CMOS battery dying, which is a little different from your BIOS… BIOS settings are stored in the CMOS which requires power to remember the settings, but a BIOS is more than just the CMOS.
If the battery goes, you will still be able to boot up, but the BIOS will use its default settings, not having the stored settings available from the CMOS anymore. This is usually annoying but relatively safe, since the default settings will generally be the most conservative. Windows will still work, although the date and time will be wrong and some peripherals may not work.
If your computer is less than three or four years old you’ll probably be able to find the CMOS battery on your motherboard… it usually looks like a dime-sized watch battery held in place by a clip. Pop it out, take it Radio Shack, show it to them and ask for a new one.
Static discharge is a tricky question… I touch metal before grabbing whatever computer part I’m messing with and that’s the extent of my static precautions, but I’m not about to tell you not to worry about it. Problems due to static aren’t always going to be obvious… you can damage components today (without seeing any sparks) and the problems show up months later. Why not err on the side of caution and pick up some of those grounding wrist straps, since you already know how to use them?
Second, don’t ever open that thing when it’s plugged into the wall…I don’t know why you
suggested that one Mangetout, but no manual I read says to ever do that with it connected
to a wall outlet.
I just changed mine last night, on a six month old Dell 4400. Unplugged. I’ll go in tonight to see if the clock keeps better time. The only CMOS setting I had to change back was the date and time.
I’d HIGHLY recommend you unplug the power cord from the PC. We have Compaq workstations at work that like to power on when jamming an ethernet card into a PCI slot. And touch the chassis to ground yourself.
The battery will have a model number on it, probably starting with a “C”. Unless you’ve got some exotic motherboard, Radio Shack should have a replacement battery for you. $2 - $3 probably.
Every manual I’ve seen makes it abundantly clear that the machine is to be plugged in during surgery. Otherwise it’s not grounded. There is no danger on working on a plugged in machine unless you’re mucking about with the power supply.
Oh for heaven’s sake. If you’re paranoid about grounding, do what I used to to before working inside a computer when I was highly worried about static:
open the computer case
while the plug is still connected to the wall, touch the metal power supply case
Repeat, unplug the computer. I have never seen anyone suggest otherwise to novices.
On computers with ATX type power systems this is even more important, as the computer may “seem off” but actually has live voltage going to the motherboard. Some, but not all, have a real off switch on the back. (Some old proprietary systems do this too, like my old Acer.) I have seen motherboards damaged by novices dropping something metal (like the battery they are taking out or inserting) and pop, there goes part of the power supply and/or motherboard.
Suggesting leaving it plugged in is seriously bad advice and would get you banned from some boards.
For pro shops, you use separate grounding straps or mats.
I have done it plugged in & never again shall I do it that way. Same thing with plugging in serial cables,
do not do that with the computer on. USB cables should be okay.
After putting in a new battery you would have to redo the Bios settings too. Seems like a
better idea to get a tech to change the battery if you don’t know how.