How to Check a Lamp with a Multimeter
- 1). Unplug the lamp and take out the bulb.
- 2). Connect the test probes to their appropriate receptacles on the multimeter. Red goes to the positive slot, and black goes to the negative, marked "Volt" and "COM."
- 3). Set the dial on the multimeter to measure ohms, or resistance. This is marked with the Greek letter omega.
- 4). Touch one end of the probe to the metal strip at the bottom of the socket, and touch the other probe to the side of the socket. You should get a nonzero measurement; if you don't, it means that the lamp's circuit is broken or shorted. A short circuit is dangerous and can cause a fire.
- 5). Touch the two prongs of the lamp's power cord using the same method -- you should get approximately the same result.