How to Test a BAD Capacitor with a Multimeter on your Power Supply

How to visually find a bad capacitor on any power board

[carlosedwardos]

You are correct about a bulging capacitor being bad, but your test of the capacitor was woefully deficient. You only tested the capacitor for capacitance, in the case of many bad capacitors I run into daily, they would pass your test as good! - what you FAILED to test for was ESR (equivalent series resistance) and even more importantly, DC leakage (which is an electrical leakage, not to be confused with a physical leakage of the electrolyte inside)

[surgingcircuits]

Not sure why you were swapping the leads/polarity on a polarized cap. Pls explain, thx.

[CollosalTrollge]

I have a cooler master and one of the 2 big capacitors has leakage, can this causing the fan of the psu to spin up and then not spin up ? intermittent behavior. I am hoping if i can change the capacitor my psu will be fine again.

[jeffreystroman]

Something I picked up from an hvac guy, after checking this measure the VDC of cap and watch it ramp down as meter bleads down the charge given by meter when checking for resistance ie short.

[RixtronixLAB]

Nice info, thank you for sharing it :)

[vant]

Unfortunately this does not always work. I once bought really cheap 64V 10uF capacitors, I have suspicions of course but multimeter and ESR meter showed normal parameters - correct capacity and 1-2 Ohm resistance. Everything was ok until I put one of them in PS filter where it should have been smoothing 17V average +- 3V ripples from flyback. It started to heat really quickly. So I guess the electrolyte leaked out but I was unable to detect that.

[newbsensei]

Very educational video sir. how about for resistance? Is there a way to determine if the capacitor is faulty thru resistance parameter? Thanks!

[diddydooffurz]

I have this option also on my multimeter but it shows 1 all the time no matter how i put it. It is a cheap one though, can this be the problem? I cannot measure the capacitor

[ngfczuj]

That multimeter you have is worth the cost.

[arpeemac]

"bulged" - that's the word you were looking for.

[alvin]

Thank you for the tutorial.My first project what am building I have apply too much heat during silder procces could it destroy the quality or other factors of the capacitor.?

[treadmillrepair]

This is a Fluke 287 or 289.
I have one Fluke 289 and many other more.

This is one of the best multimeters of Fluke but if you want to test capacitors is better to use a n ESR meter.

Cheers.

[ashleymcgovern]

Agghvwas looking for about new solid state capacitors. You can tell a bad older style capacitor by looking at it, like you show (bulging or burst caps etc). I wanted to see if there were any tell tale signs for solid types? Guess I'll just have to test them with the meter from the backside of the board.

[peteleoni]

Note to viewers: basically starts @ 3:30, amounts to: You can test a capacitor with a capacitor tester, bad capacitors bulge"

[whoami]

man, have any idea how to test a film capacitor KNB2520 class Y

[anotherOneMore]

Is there a way to test a capacitor it without removing it from the circuit?

[gersanaqq]

nice multimeter even if its set to continuity it still gives the reading for nf..

[SalimKhan-gkfh]

The word is bulged when the top of the capacitor is bulky as you called it it is ‘bulged’

[ondaride]

This is too obvious. Very often bad one and good one show same reading so whatchagonna do?

[MrOner]

thank you for this knowledge video..keep it up!