"Paul" wrote in message
oups.com...

Thanks for the response. How can I findout if the capacitor is open.
With a multimeter, can I test the resistance across the terminals to
check for continuity (not sure if this is the right way to test a
capacitor?)


An ohm meter will show a low resistance and then climb to an open circuit
with a good cap as it charges. A bad cap will only show an open circuit.
There are capacitance meters that will indicate how many microfarads the cap
is; some high end digital multimeters can check caps. One thing, with the
power removed from your garage door opener, short out the cap with a
screwdriver first just in case there is any voltage still stored in the cap.
Multimeters do not like getting hit with a 110V spike if the cap is good.

Ok, a low tech and very dangerous way to check - with the motor humming on
your opener, see if you can give the motor a nudge to get it spinning.
Please use something other than a finger or hand to try this out, but if the
opener works, then it's a bad cap.

Hope this helps.

Bob.