bad capacitor

[fogus]

How do u check for failed capacitor?

 

[Klaus]

You can do a quick check with an old fashioned multi meter ( with pointer) on the Ohm scale. First short the capacitor terminals to make sure its discharged. Then place the meter probes to the capacitor ( short removed) and observe the meter's needle as you do so. It should briefly kick up to some low value Ohms then go to infinity. If you now reverse the meter leads you will observe the same effect. This indicates the capacitor is accepting charge, ruling out an open or short circuit.
If the meter always reads zero there is a short, if it does not kick you *might* have an open circuit.
On very small value capacitors you will not see the needle jump, there's too little charge for that.
You can also check the value with a capacitance meter. Some digital multi meters have such a range. Make SURE you discharge the capacitor first before connecting it to a digital meter.
Klaus