Make sure your device is unplugged and turned off before you find the capacitor.
Use caution when working with electricity. A strong enough shock can cause serious harm or death. Make sure the screwdriver’s handle doesn’t have any cracks and that no bit of metal is sticking out the back. This could carry voltage and cause you serious harm.
Gloves can be purchased at your local hardware or home improvement store. Don’t use large rubber gloves because they will give you less dexterity while you’re working.
On a capacitor with more than 2 terminals, the positive terminal may be labeled “common” instead.
Do not hold onto the metal part of the screwdriver while making the connection. Capacitors can store a lot of energy and the resulting spark or current can result in serious injury.
Make sure the capacitor you’re testing is completely discharged or the circuit is off before using a multimeter. Too high of a voltage can damage the meter or cause you harm. [9] X Research source Digital multimeters can be purchased hardware or home improvement stores. Capacitance is measured in farads (F).
Wear gloves while testing with a multimeter if you’re worried about any residual charge.
Write down the capacitance number after you take a measurement so you can remember it. If the numbers do not move at all, the capacitor is considered open and needs to be replaced.
If the capacitance number went up infinitely to the limit of your multimeter, the capacitor has shorted out and should be replaced. Some capacitors will have a set capacitance with an acceptable percentage of variance. For example, if your capacitor says “50 ±5%,” the acceptable capacitance range is 47. 5 to 52. 5 F.
