Multimeter. The multimeter needed to perform these tests is a bit 'expensive ($ 10) a similar handheld with a stylus deflection and operated by one AA battery. Multimeters, although they may have different sizes of mail, only two will be needed from the 150 VAC (volts alternating current) and resistance (ohms) those. Otherwise, a multimeter is retained in determining the savings battery.For mini-lights, a multimeter can be used to test circuits issues.The following voltages (120 VAC) when plugged into an electrical outlet. Self-employment is the son of wire attached to each bulb in a string of three children. The continuity of the two 3-amp buss fuse in the plug if the circuits do not work during the experiment, while plugged in. The continuity of each circuit wire (hot and cold) if the circuit does not function tests. Continuity of individual bulbs (eg, for lack of work and filament shunt bypass, and a little son of lead corroded). Security. For 120 volts of electricity through most of the minigames in lights, basic safety and proper procedures are essential for the test. People who know nothing about electricity, or how to use a multimeter, to read at least on these topics. Better yet, get hands on training on them. Otherwise, the chain and a multimeter may be damaged, not to mention the machine itself or 1 herself.Step. Circuit test. Connect the non-working channel to a working outlet. Set the multimeter to 150 VAC. Insert a multimeter probe in each of the two female sockets. (Spine Most are two mini-poles.) Reading should be about 120 VAC, which means that the circuit is good. Unless reading occurs, check the contacts in the socket of the probe. If there is still no reading, disconnect the chain and take step.Step next 2. Fuses intended to test continuity (unplugged). Slide the door panel on the spine. Set the multimeter to the optimization of moderate resistance (cheap multimeters will have a single parameter). Touch probes its entirety. The reading should go to zero, ie, the default zero.Touch August multimeter probe to each end of a fuse once. If the reading is zero deviation for each fuse are good. If not, replace those that do not break the continuity, can be found at hardware stores. It might be easier to test this by removing the fuse first, and then test each plug.Step outside male 3. The son of the test circuit for continuity (unplugged). If the fuses are ok, at this point, insert a multimeter probe (always with the resistance) in one of the sockets female, while the chain is still disconnected. Touch the probe one another plug-in for male leads at the other end of the chain. If there is reading, getting the first actor to others, instead. One of the two male leads have to give a reading of zero for a good (solid line) in continuous time. Perform the same test socket.If female secondary plug, is the son does not give a continuous reading is something wrong with the wiring of the circuit. Visually inspect the son of damages. Repair the damage, if found, and retest them. If the child now show the continuity of the circuit, and the bulbs are not yet, go to step.Step 4 next. Bulbs individual tests for continuity (unplugged). Because the bulbs in question must be removed for this test, this process is much slower than their examination with a magnifying glass and backlight. Yet, surprisingly, a few bulbs that seem to agree with the magnifying glass can not agree with the multimeter.Thus test probes of a multimeter to make good contact with each child to connect to a light bulb successful test. Such contact may be provided by the scraping of the bulb over the head with a cutting tool with a brilliant first test. Replace bulbs Test Bad (UPS). Conclusion. Experts indicate the duration of the mini-bulb filament 3 to 5 years, depending on its degree of use. After maintaining these strings of lights for the period of time, it's time for new channels. If the same type of purchase, the former can be used for spare parts and bulbs. However, the LED (Light Emitting Diode) strings might be a good option to consider at this point.