How to Troubleshoot an RC Circuit Capacitor

Turn off the RC device. Remove the batteries powering the device, if installed. Locate the capacitor for testing.

Discharge the capacitor's stored energy by touching an exposed copper wire to both leads protruding from the capacitor. Hold the wire by an insulated covering or at an electrical tape wrapped portion to avoid electric shock. For larger capacitors, use a screwdriver with an insulated handle. Touch the metal shaft of the screwdriver to the capacitor leads. Keep the wire or screwdriver shaft across the leads for at least 30 seconds to discharge the full contents of the capacitor.

Adjust your multimeter to measure "ohm." Touch one of the red or black multimeter prongs to one lead protruding from the capacitor. Touch the remaining multimeter prong to the remaining capacitor lead. Monitor the ohm measurement reported by the multimeter.

Determine the capacitor's capability to collect and store a charge. Good capacitors initially read zero on the multimeter followed by a slow, but continuous increase toward infinity. Shorted capacitors constantly measure zero on the multimeter. Capacitors in an "open" state, do not show any reading on the multimeter. Leaking capacitors behave similarly to good capacitors, only the charge stops during the slow climb toward infinity as electricity leaks.

Inspect all the capacitors for bulges, heavy corrosion, leaks or other obvious damage.

Replace capacitors that are damaged, reporting an "open" state, leaking stored charges and capacitors that are electrically shorted.