In his new book, "The Choice," Bob Woodward, assistant managing editor of The Washington Post, related a tale about Bob Dole and Colin Powell. Before announcing his candidacy and well before Powell declared his disinterest in elective office, Dole drove to the retired general's home for a meeting. Dole rang the bell a number of times but no one answered. Worried that his potential rival for the nomination might have stood him up, Dole called Powell, using his car phone. Powell said he'd been having problems with his doorbell. "You've got to get that fixed," Dole said.

If your doorbell currently is in a state of disrepair not unlike that of the former chairman of the Joint Chiefs of Staff, and you don't want to miss an important caller, read on.

A doorbell system is low voltage 10 to 24 volts and is fairly safe to work on. Even so, we recommend that power be turned off before taking on any electrical project.

With a doorbell, there are four basic system components: 1) the button, 2) the chimes, 3) the transformer and 4) the wire. Testing the button is easiest. First, remove the mounting screws. Next, use a screwdriver to loosen the terminal screws on the back so that the two wires can be removed. After the wires are completely removed, touch them together. If the chimes sound, the system is operational and the button will need to be replaced.

The second step involves testing the chimes. If you were an electrician, you would own a volt meter which would make testing the system easy. Chimes are electrical devices that some stores will not allow you to return. So, don't assume that you will be able to purchase new chimes to make the test, and then return them if they are not needed.

If you have two sets of chimes on your system and both have stopped working, there is a good chance that something else is wrong. Two chimes breaking at the same time is unlikely. If you have two sets of chimes and only one has stopped working, it is likely that the chimes that have stopped functioning are damaged. Swapping the chimes will tell the tale. If you discover that the good chime also works at the location where the other wasn't working, one new set of chimes is needed. If the good chimes don't work at the bad location, the wiring is probably damaged or the transformer has burned out.

If you have only one chime, ask a neighbor if you can borrow his to test your system. If his chime works where yours doesn't, yours needs replacement. If your neighbor's chime doesn't work when connected to your wiring, your chimes are probably OK and your wiring or transformer may be the culprit. With the chimes and button tested, the problem is narrowed down to either the wiring or the transformer. The transformer is normally located in the ceiling of a closet or in the garage. In some cases it is mounted in the attic, but this is rare. Purchasing and replacing the transformer is far less expensive than hiring an electrician, but it does mean working on the high voltage part of the electrical system.

Two terminals on the transformer hold the wires that make up the chime circuit. There also are two wires (not terminals) that come out of the transformer that connect to the house electrical system normally 110 volts. Just like a light fixture, it doesn't make any difference which way the wires are connected as long as the high voltage wires are connected to high voltage lines and light gauge wires are connected to the screw terminals. This is a replacement that you can't get backwards unless you are a real klutz. Unlike the chimes, we do not recommend that you borrow your neighbor's transformer. Keep fooling around with high voltage in your own backyard. If the transformer has been replaced and the system still doesn't work, there is probably a broken wire somewhere. If all of the wiring that is visible seems to be in good condition, you have done about all you can short of calling in an electrician. To a dyed-in-the-wool do-it-yourselfer, we suggest an ohm or bell test and rewiring. For everyone else we suggest looking into a wireless system. Considering the cost of an electrician and the many hours that it can take the best technician to find a break in the wire and/or replace it, the average consumer is going to be dollars ahead with an easy-to-install wireless system.