A touch lamp utilizes a sensor that lets you turn the lamp on or off with the touch of your hand. It can be more difficult to repair a touch lamp because you must disassemble it befor replacing any parts. You can do it by following these steps.
Troubleshoot the problem. Make sure it's not as simple as a bad bulb or a faulty electrical outlet. If the wall switch controls the outlet, make sure the switch is on.
Unplug the touch lamp, and pry off the bottom with a butter knife. Check that all the wire connections are inside the lamp. If necessary, cut and rewire with wire nuts.
Replace the touch sensor located at the base of the lamp. Purchase one at any electrical supply store or home improvement outlet, and follow the manufacturer's installation instructions. Installation mostly involves nothing more complicated than following the color-coded wiring.
Check any fuses inside the lamp. Some newer touch lamps have soldered-on fuses. Replace any burnt fuses with fuses that carry the same rating.
Install a new power control transistor, called a thyristor or TRIAC. You'll find this on the circuit board in the base of the lamp. The power control transistor is the largest component on the board. Remove, place the new one in the board and solder into place.
Unplug the touch lamp even when changing a bulb; constant contact while changing the bulb can burn out the touch sensor. Plug the touch lamp into a surge protector to avoid any short circuits due to power surges.
Do not plug a touch lamp into any outlet that a dimmer switch controls. Consult an electrician if you can't repair the lamp yourself. Always unplug a touch lamp before you repair it.