A malfunctioning electrical socket is something almost everyone will experience. A dead receptacle can have many possible causes, including tripped circuit breakers or blown fuses, an open neutral wire, an open hot wire or a faulty receptacle. On a multiple outlet branch circuit, an open hot wire or neutral wire occurs when someone removes one of the receptacles upstream from the dead one without properly splicing the wires together after removing the receptacle.
Check to see if the circuit breaker has tripped or the fuse has blown. When a circuit breaker trips open, the breaker's handle will move to the centre position, but this does not always happen with older breakers. Move the breaker's handle all the way to the off position and then turn it back on to reset it. In the case of Edison base fuse, you will be able to see through the glass window to determine if the fuse element has melted. A blown fuse will need to be replaced.
Set the function switch on your digital multimeter to the 250 volt alternating current (AC) range and insert the probes into the two slots on the receptacle. If the power has been successfully restored to the receptacle, the meter will read approximately 120 volts. If the meter reads 0 volts, you will need to remove the receptacle from the device box.
Turn off the circuit breaker or unscrew the fuse. Remove the receptacle cover plate and the two 6-32 screws securing the receptacle in the box. Pull the receptacle from the box and remove the tape covering the terminal screws if they were covered with tape.
Turn on the circuit breaker or replace the fuse. Touch the probes of your digital multimeter to the brass and silver coloured screws, the ones with the black and the white circuit wires attached to them. The meter should read approximately 120 volts. If the meter indicates 0 volts, move the meter probe that was touching the screw with the white wire attached to it to the bare grounding wire. If the meter now indicates 120 volts, the problem is an open neutral wire. If the meter still indicates 0 volts, the problem is either an open hot wire or a bad circuit breaker.
Locate the next receptacle on the circuit that is working. The break in the circuit will usually be in that receptacle box. You will have to remove that receptacle and repair the broken connection. If all the receptacles on a multiple receptacle circuit are dead, the problem is a defective circuit breaker.
There is always a chance that a wire has broken somewhere in the cable but that doesn't happen very often. If someone has recently hung pictures, installed shelves or done something else that involved driving nails or screws into the walls, there could be a damaged wire behind the wall.