There are four kinds of things in your home: stuff that is supposed to move (mechanical), stuff that isn't supposed to move (stationary), electrical stuff, and, finally, stuff that does more than one thing (such as electro-mechanical). For example, a windup alarm clock is a mechanical thing -- it's supposed to move gears and hands. If components don't move, it's broken. What all of these mechanical things have in common is that they technically are "machines." That is, they convert one form of energy into another. A hand tool, for example, converts your energy into strength to turn a bolt or cut a board. Knowing what it is supposed to do is the first step in fixing it. A mechanical clock stores your energy in a spring and slowly releases it to turn the clock hands.

Troubleshooting mechanical things is a little more difficult than troubleshooting stationary things because you may have to take something apart. However, if you know what your broken item is supposed to do, you probably can figure out what needs fixing. For example, a windup alarm clock may run very slowly, not keeping the correct time--and making you late for work. Rather than toss it and get another one, carefully open it up and see if there's anything (a loose screw, dust) keeping a mechanism from turning as designed. Or the item just may need a small amount of lubricant to reduce resistance between moving parts.

Lubricants decrease friction between moving parts, and are a vital part of fixing things. Many lubricants are petroleum based. Thin lubricants are called oils and thicker lubricants are greases. Here are the most popular household lubricants and what they work best on:

* Machine or penetrating oil (such as WD-40) is a general lubricant for small moving parts.

* Silicon spray is a multipurpose product that lubricates, waterproofs, and reduces corrosion.

* Graphite powder and spray is a fine powder lubricant (sometimes in a base of light oil) for lubricating locks, bearings, and other very small parts.

* Penetrating oil lubricates as well as reduces and cleans corrosion from metal parts.

* Lithium grease is a petroleum-based grease with lithium powder in it to enhance lubrication of larger moving parts such as automotive gears.

* Silicone is an organic compound that is highly resistant to wear, heat, and water; it makes a great lubricant.

Of course, the largest category of stuff we all own is: hybrid. They do more than one thing. Clothing (stationary) includes a zipper (mechanical). A food processor (mechanical) requires power (electrical).

So fixing hybrid things is simply a matter of understanding what it does and figuring out whether the problem is stationary, mechanical, or electrical. That quickly narrows down the repair job. For example, troubleshooting a lawnmower means looking at the handles and case as stationary; the wheels, engine, blade, and controls as mechanical; and the starter and ignition system as electrical. If the engine runs, but the mower won't move, check the controls or the wheels. You can break down any household thing to its systems, then components, to figure out what's wrong with it and how to fix it.

What about all the new gadgets coming on the market every day? Most really aren't new; they are new-and-improved versions of things that have been around for many years. For example, the new DVD/CD players are simply hybrid gadgets that use electricity to do mechanical things. Think of household things by their basic function and you can easily troubleshoot and fix them. You can outsmart broken stuff -- and save some money.