How to Test TV Capacitorsby Brandy Alexander
Capacitors are electrical components found in nearly all electrical devices. Used to filter or store electrical charge, capacitors can fail over time and cause TVs they are in to malfunction. Replacing a malfunctioning capacitor is cheaper than replacing an entire TV, and all that is required is a digital capacitance meter and a little time. Since capacitors can fail, you should start troubleshooting problems with TVs by testing their capacitors.
Turn off and unplug the TV. Wait for 10 to 15 minutes to be sure the working capacitors will be relieved of any residual charge.
Remove the cover on the back of the TV with the screwdriver to gain access to the TV's circuit board.
Identify the capacitors you wish to check. Make a note of the rating printed on each capacitor's body. This is the rating you will test.
Connect the tip of the black negative probe from your digital capacitance meter to the shorter of the two terminals of the capacitor. If the two wire terminals protruding from the capacitor are of the same length, then the capacitor is not polarized, and the negative probe lead can be connected to either.
Connect the tip of the red positive probe lead to the other terminal on the capacitor.
Rotate the dial on the meter to measure capacitance at one level higher than the printed value. For example, if the capacitor is rated at 470uF and your meter has a selection for either 200uF or 2000uF, you will need to select 2000uF in order to obtain an accurate reading.
Read the display on the meter. If the value read by the capacitance meter is more or less than 10 percent of the rating printed on the capacitor, then it is working properly. If not, the capacitor is damaged and should be replaced. For example, if your capacitor was rated at 470uF and your meter reads 400uF, it should be replaced; if it reads 450uF, it is working properly.