The fuses or circuit breakers in your home electrical system are there for a purpose: to blow or trip if the circuit is overloaded. When that happens, as it does from time to time in almost every home, what do you do?
The first step should be taken even before a circuit trips. If you haven't already done so, make a list of all the branch circuits in your home by number and by what area each one controls. Then you can figure out which receptacles and fixtures are on each branch circuit. If you aren't sure the list is accurate and complete, you can verify it with a very simple procedure. Remove a fuse or trip a circuit breaker to its OFF position, then check to see what equipment or devices are deenergized. Of course, it's easy to see when a ceiling light goes out, but you can check a receptacle just as easily by plugging in a lamp. A small night-light is an ideal indicator. Once you know exactly which receptacles, fixtures, and appliances are connected to each branch circuit, write all the information on a card, and attach the card inside the door of the main entrance panel.
When a circuit goes off, there may be some visual or audible indication of the trouble spot, such as a bright flare from a lamp or a sputtering, sparking sound from an appliance, that will immediately lead you to the source of the trouble. If so, disconnect the faulty equipment. Take a flashlight, and go to the main entrance panel. Check to see which fuse is blown or which breaker has tripped, and determine from your information card which receptacles, appliances, and lighting fixtures are on the circuit. Then disconnect everything on that circuit you can, and inspect those fixtures you can't easily disconnect for signs (or smells) of malfunction.
Replace the fuse, or reset the breaker. If the circuit holds, it's possible something you disconnected is faulty. Check for short circuits or other problems. If there's no evidence of electrical fault in the fixtures, the problem may be too much current draw for the circuit to handle. In this case, remove some of the load from the circuit.
If the new fuse blows or the circuit breaker refuses to reset, the problem lies in either the equipment that's still connected or in the circuit cable itself. Check the still-connected items, examining each for faults until you find the offending equipment. If the circuit still goes out when there are no loads connected to it, the wiring is faulty, probably due to a short in a junction or receptacle box or in the cable itself. If you suspect faulty electrical wiring, call an electrician.
A circuit breaker is a remarkably trouble-free device, but once in a while a breaker does fail. The result is the circuit will not energize, even when it's fault-free. When a circuit goes out, if the circuit breaker itself has a distinctive burnt plastic smell, if the trip handle is loose and wobbly, or if the breaker rattles when you move it, the breaker has probably failed. Turn off the circuit, check the breaker with a continuity tester, and replace it as needed.