SMD capacitors?

[dds]

How can I test them on pcb?

[PCBONEZ]

Re: SMD capacitors?

You test them the same as other caps.

.

[starfury1]

Re: SMD capacitors?

capacitance meters are designed to test on board...they use low AC frequency
if I remember correctly

of course to be absolutely sure it best to remove, but SMD is a bit of a pain
so best is "If in doubt replace"
(if you dont have proper removal tool 2 irons can do the job)

larger electrolytic type tantalum ones are prone to failure (+ on them in uf range)
smaller ceramic types will mostly probably be ok
but all caps can fail
(and there has be cases of them cracking there ends off due to stress)

welcome & cheers

[dds]

Re: SMD capacitors?

Can I get some recommedations for a good Capacitance meter?
I have a Extech RC100 SMD capacitance meter which is totally unreliable
for in circuit measuring (works fine outside circuit with smd capacitors)

Thanks

[PCBONEZ]

Re: SMD capacitors?

SMD are measured the same as other caps.

If it's in the circuit and there are other caps in parallel either directly or indirectly then in-circuit testing won't work.
- There are usually other capacitances in parallel in-circuit.

That's probably what your problem has been.
Not the meter.

.

[dds]

Re: SMD capacitors?

SMD are measured the same as other caps.

If it's in the circuit and there are other caps in parallel either directly or indirectly then in-circuit testing won't work.
- There are usually other capacitances in parallel in-circuit.

That's probably what your problem has been.
Not the meter.

.

Thanks for your reply. But I'm more confused, how can I reliable measure capacitance in circuit?

[PCBONEZ]

Re: SMD capacitors?

I don't know what you don't understand.

If there is nothing in parallel then you put a lead on each end and measure it.

If there is something in parallel you remove at least one end from the circuit and do the same thing.

.