I have a ceiling fan in my living room, which has sockets for 3 candelabra bulbs. When there were incandescent bulbs in it, it worked perfectly. I replaced the incandescent bulbs with 3 LED bulbs. 2 of the bulbs work fine. I noticed one bulb would go visibly dimmer than the others at random. It would stay that way for a while, then randomly get bright again. This happened over a course of several months, until the bulb just died. I assumed it was just a defective bulb. However, I replaced the bulb and the same thing is happening. It could be wiring, but I dont know why it would be so inconsistent. Additionally, the fan is never on. So its not as if the vibrations of the fan are moving the wires.
Im not sure where to begin troubleshooting. Ideas?
I am an Electrical Engineer, and I noticed this behavior several times, when I replaced incandescent bulbs in fan lights. The switch that controls the light must be connected to a circuit that switches the AC via a transistorized circuit. When switched off the incandescent bulb acts as a load to consume a small leakage current without reaching a high enough temperature to emit light, but an LED does emit light for this tiny current. So the solution is to consume this leakage current. If an incandescent bulb is put in one of the four sockets the problem is solved, but there is a mismatch in light and a loss of efficiency. A special bulb adapter can fix it.
I would look at the socket also, many times When incandescent and cfl’s lamps had this issue I would find the center contact not firmly connecting , with the power off lift the center contact away from the base and see if this fixes the problem. I think it was a heat problem on the incandescent lamps as I don’t see it very often now that 100w lamps are so expensive and the cfl’s could not always screw all the way in, lifting the center contact in the socket solved many inconsistent to no light problems just as you have. If you still have the original light look at the base it may be etched off from arcing and that would indicate a loose connection you can fix by pulling it up a little.
I have solved the issue. I sprayed the inside of the socket with (electric) contact cleaner. I then took the dead bulb and screwed it in and out a few times to work the solution around the metal of the socket. I then let it dry. Just for good measure I sprayed the socket with some canned air. The issue is fixed and has stayed working properly for months, so far.