The MG-B sports car that I drove in my youth owned me. I regularly changed and gapped the plugs, replaced the points, set the timing and replaced parts that fell off.

That was many years ago. I still have a two-seater sports car, but it is so complicated that, quite seriously, I can't figure out how to set the clock on the dashboard.

Computers have followed the same path when it comes to working on them yourself. Most modern users are about as likely to work on their microwave ovens as their computers.

But there are some under-the-hood maintenance jobs that are still simple enough for almost any home user. Today we'll talk about some jobs most readers can tackle themselves. I'll divide things up based on skill level.

Beginners

Even if you are barely competent to punch the power button, there are still some jobs you can safely take on.

Adding memory: Memory chips literally snap into place. Use a Web site such as www.crucial.com to find the type of memory your computer uses. Buy it online or locally and install it yourself.

Installing new devices: Printers, scanners and memory card readers for digital cameras are easy to install. It usually involves no more than adding some software and plugging the device in.

Intermediate

Hard disks: Replacing or adding a hard disk sounds impressive when you brag about the job to friends or a spouse, but it's really easy. Most hard disks come with easy instructions these days. There are just two connectors to snap into place --- one for power and one for data. Most modern computers recognize the new hard disk with no tinkering.

Video cards: When one of my older computers couldn't handle my latest game, fixing things was as easy as replacing my old video card with a better one. That also made the computer more responsive when performing other tasks. You'll find good directions with any new video card. Look for one with 128 megabytes of memory or more. Use the supplied CD to install the software that comes with the card, then turn off the power, pop out the old card and push the new one in place. Tighten one screw, plug the monitor back in and you're in business.

Advanced tasks

Power supply: When you push the power button and nothing happens, it's likely your power supply has failed. Most computer stores stock an assortment of replacement units. Get one that (a) offers a wattage rating at least as high as the old one; and (b) fits into the space taken up by the old one. It's an easy job for someone who feels comfortable inside the computer.

Motherboard: The ultimate upgrade for a computer involves replacing the motherboard --- that's the main circuit board. It houses the processor and memory chips. Replacing the motherboard is almost equivalent to creating a new computer. You'll find motherboards at most computer stores. Just make sure the new board fits into the computer chassis. Also take notes --- or even digital photos --- as you remove the old board. That way you'll have no problem making all the connections when you install the new one.

Don't try this at home

There are some jobs that no amateur should tackle. For instance, never take a monitor apart. High voltages lurk inside, even when the monitor is unplugged.

Nor should you tinker with the innards of a hard disk --- it's mildly entertaining but a guarantee for disaster.

Whatever task you're tackling, go slow and use common sense --- even when you're an experienced hand.

Static electricity can zap a memory chip or other component, turning it into an expensive piece of trash. RadioShack and other outlets sell grounding straps that attach to your wrist and help you avoid static buildup.

If you don't want to go that far, at least touch the chassis of the computer before grabbing the chip.

Be safe and go slow, but give do-it-yourself computer repair a try. Besides saving a few bucks, knowing your way around the inside of a computer can be a lifesaver when your machine takes a long nap some fine Sunday.

tecbud@ajc.com