I have an electrical outlet that stopped working. I replaced the outlet, still not working. I tested the outlet for power using my sperry meter and I have power. Why would it still not work?
There are several reasons you can read a voltage and have an outlet not work. The most common is failed backstabs in the outlet that is dead or the one prior to it. It could be a problem with the hot or the neutral causing the outlet not to power something that draws even a small amount of current but a high impedance meter draws almost no current and a slight carbon path or capacitive coupling can provide enough potential to register the voltage.
The second can be the same kind of failure where the wire has no connection of any kind or a tripped circuit breaker, but is running parallel to and many times in contact with a live circuit. The live cable induces a voltage on the dead one because there is no load your meter can measure the voltage, add a light or power supply it won't work and any voltage reading taken before is almost gone this is where the term phantom voltage comes from. Transformers use the same thing to do there job but there are hundreds of wraps of insulated wire in close proximity.
Now to fix the problem. Most of the time I have found the wires pushed into the back of the outlets to be loose if not the outlet go to the first working outlet and check the wires on that one the feed to the next outlet has failed. It is possible that one of the wires have broken or come out of a wirenut but backstabs are the cause for 98% of these failures in my experience. Make sure to turn the breaker off when pulling the devices and good luck.