Testing if a capacitor works

SupaGu · 1st March 2008, 3:34 PM

I have 2 capacitors and a crystal in a oscilator type circuit. I have tested the crystal and it looks to be working, now i want to test the capacitors as the circuit which should work isnt working, I have a 5v power supply, some LED's can i set up some easy test i can test which capacitor isnt working? preferable without removing it from the circuit

dephilile · 1st March 2008, 4:04 PM

If you have a really good multimeter you can probably use that though i’m not sure how accurate it would be in the nano/picofarad range and you would probably have to take the capacitors off the board. Probably easier just to replace both the capacitors.

It could be a bad solder joint or something causing problems. Try re-flowing the solder on the components.

How did you check that the crystal is working?

do you have access to a CRO?

SupaGu · 1st March 2008, 5:18 PM

i plugged it in to a microcontroller dev board and it worked fine.
I have a osiliscope

1st March 2008, 3:34 PM	#1
SupaGu Member Join Date: Jun 2007 Location: Adelaide, Australia Posts: 453	Testing if a capacitor works I have 2 capacitors and a crystal in a oscilator type circuit. I have tested the crystal and it looks to be working, now i want to test the capacitors as the circuit which should work isnt working, I have a 5v power supply, some LED's can i set up some easy test i can test which capacitor isnt working? preferable without removing it from the circuit

1st March 2008, 4:04 PM	#2
dephilile Member Join Date: Jun 2006 Location: Daejeon - South Korea Posts: 944	If you have a really good multimeter you can probably use that though i’m not sure how accurate it would be in the nano/picofarad range and you would probably have to take the capacitors off the board. Probably easier just to replace both the capacitors. It could be a bad solder joint or something causing problems. Try re-flowing the solder on the components. How did you check that the crystal is working? do you have access to a CRO?

1st March 2008, 5:18 PM	#3
SupaGu Member Join Date: Jun 2007 Location: Adelaide, Australia Posts: 453	i plugged it in to a microcontroller dev board and it worked fine. I have a osiliscope