DO-IT-YOURSELF : Shedding Light on How to Rescue a Favorite Lamp From the Trash Heap

If your favorite lamp--even with a new bulb--doesn’t light anymore, don’t throw it out. The working parts of a lamp (plug, cord and switch) do wear out, but they are easily replaced and you can do the job yourself.

First, identify the problem. Unplug the lamp from the electrical outlet and check the plug. If the prongs are bent or corroded, or if the insulating plate (the cardboard or plastic piece between the prongs) is missing, the plug is unsafe and needs to be replaced.

Inspect the lamp cord along its full length. If the sheathing is frayed or cracked, or if wires are exposed, the cord should be replaced for safety. That means rewiring the lamp.

If the cord and plug are intact, chances are the socket (the metal holder for the bulb and switch) is faulty and needs replacing.

To replace a plug

* Remove the old plug by prying it apart with a screwdriver and loosening the screws that hold the wires.

* If the cord is flat, you can clamp or snap on a new plug designed for easy installation (available in most hardware stores). Follow directions on the package.

* If the cord is round, remove 1 1/4 inches of the cord jacket (the outer covering of both wires) and three-quarters of an inch of the wire insulation (the covering around each of the two individual pieces of wire) by carefully cutting through the outer material with a knife. Tie the insulated part of the wires in an Underwriter’s knot (loop the wires away from the each other, feed the ends through the loops of the opposite wire, and pull gently). Twist each bare wire end clockwise and connect it to one of the screws in the plug. Tighten the connections by tightening the screws with a screwdriver.

To rewire a lamp with new cord

* Unplug the lamp and remove the shade and bulb.

* Remove the harp (the metal frame that holds up the shade). Lift the sleeves at the bottom of the harp’s arms, which exposes the clips that hold them. Squeeze the arms together to release them from the clips and free the harp.

* Pry off the base cover (often a felt pad) and undo the nut which holds the lamp’s center pipe. Pull the pipe partway out of the top of the lamp.

* Remove the socket shell by squeezing it near the word press and lifting it off. Also remove the cardboard insulating sleeve, which reveals the terminal screws for the wiring. Loosen the terminal screws, so that you can remove the old wiring.

* Split the top two inches of the new cord and strip the insulation off the top half-inch of each piece of wire. Cut the old cord with a knife or a wire cutter about a foot below the base of the lamp. Split the cord and strip the ends of each wire so that you can splice them to the ends of the new cord. This allows you to easily pull the new cord up through the center pipe and the socket cap. When the new cord is pulled through, undo the splice and discard the old cord. Form the exposed ends of new wire into loops.

* Tie an Underwriter’s knot with the two wires of the cord. Hook the wire loops over the terminal screws--the hot (smooth-sheathed) wire on the brass screw and the neutral (ridged-sheathed) wire on the silver screw. Tighten the screws to secure the connection.

* Reassemble the socket and switch into the socket cap and replace the insulating sleeve and outer shell. Tighten the nut at the base of the center pipe and reassemble the rest of the lamp.

Replacing socket-switch

* Be sure you choose a replacement socket with the same amperage and voltage ratings as the old socket (usually stamped on the shell).

* Unplug the lamp and remove the bulb, the shade and the harp. Lift off the old socket shell and insulation sleeve and disengage the wiring as described above. Undo the set screw at the base of the socket cap and remove the rest of the old socket.

* Thread the lamp cord through the new socket and secure the new socket base with its setscrew. Attach the stripped wire ends to the proper switch terminals (smooth-sheathed, or hot, wire to the brass screw and ridged-sheathed, or neutral, wire to the silver screw).

* Reassemble the rest of the socket.