The most common ways a receptacle fails is a tripped circuit breaker or tripped GFCI. If a standard receptacle is connected to the load of a GFCI and the GFCI trips, power will be shut off to the standard receptacle. Standard receptacles in kitchens, bathrooms, and outside, are likely to be connected to the load of a GFCI.
Less common ways a receptacle fails is loose wire(s) to the receptacle terminals, or the receptacle fails internally (power is present at the receptacle terminals but not at the plug end).
Electrical outlet is a very common name for a receptacle. Many home improvement stores use the term “electrical outlet” when referring to a receptacle. Outlets are the points at which the electrical system are accessed (receptacle outlet or lighting outlet). A lighting outlet is an electrical box where a light fixture is mounted and gets power. A receptacle outlet is an electrical box where a receptacle is mounted and gets power.
A plug should always fit tightly into a receptacle. A receptacle uses tension on the plug’s prongs to maintain a tight connection. If a plug is loose or falls out of a receptacle, the receptacle needs to be replaced. A loose plug can cause excessive heat and possibly damage whatever is plugged in to the receptacle.
The best way to test a receptacle, including a GFCI, is with a receptacle tester. A test may be done to determine if power is present at the receptacle or if it is wired properly. This tester will show the status of the 120 V, neutral, and ground. A receptacle tester does not have a battery.
A switch operates one half of a split receptacle. The best way to test a split receptacle is with a receptacle tester or a voltage detector. Turn the switch on and off to see if the receptacle has power (tester lights up with power). For more information, see split receptacles.
Receptacle tester shows normal or Voltage tester light is on
The light fixture at left has power through the electrical cord. If a switch operates this receptacle, then it is OK. If the fixture does not light up with a known good bulb installed:
Receptacle tester shows power off or voltage detector light is off
No power to receptacle:
Loose wire makeup, loose connection to switch, light fixture, or receptacle terminal inside of the electrical box.