Author Topic: capacitance and ESR for this capacitor?  (Read 2109 times)

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Offline kgavionicsTopic starter

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capacitance and ESR for this capacitor?
« on: May 31, 2017, 01:47:17 am »
Hi
Someone gave me away a 50inch plasma tv that doesn't turn on.i took it apart and i right away i noticed that there's two bulged caps 3300uF 100V.To be sure that the problem is coming from these caps i desoldered them and measured the capacitance and the ESR.
C was around 2750 uF for both ( which i found quite low even with 10% tolerance)
ESR was 0.13 ohm.
According to Esr table found on internet ESR should not exeed 0.1ohm for this type of capacitor.
My question: are these caps good or not?
thanks in advance
 

Offline ahbushnell

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Re: capacitance and ESR for this capacitor?
« Reply #1 on: May 31, 2017, 02:57:08 am »
If they are venting gas they are dead. 

How did you measure the ESR? 

Andy
 

Offline kgavionicsTopic starter

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Re: capacitance and ESR for this capacitor?
« Reply #2 on: May 31, 2017, 03:09:02 am »
If they are venting gas they are dead. 

How did you measure the ESR? 

Andy
thanx Andy
The only way to figure out if the capacitor is good is capacitance and ESR.
i measured ESR using a cheap Chinese component tester bought from ebay.

 

Offline ahbushnell

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Re: capacitance and ESR for this capacitor?
« Reply #3 on: May 31, 2017, 03:30:47 am »
I think it's bad.

Hook it up to a DC power supply and charge the capacitor.  Does it draw current?  Make sure the polarity is correct.

Andy
 

Offline bsalai

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Re: capacitance and ESR for this capacitor?
« Reply #4 on: May 31, 2017, 10:53:43 am »
I'd order some new ones. Bulging caps are so often the problem that it's worth a couple of dollars to replace them. I've fixed a few things this way.


Sent from my iPhone using Tapatalk
Brad, W2EK
 

Offline cnqhdszq

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Re: capacitance and ESR for this capacitor?
« Reply #5 on: June 01, 2017, 03:41:13 pm »
you  had better to test The capacitor with a LCR Bridge  .
 

Offline cnqhdszq

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Re: capacitance and ESR for this capacitor?
« Reply #6 on: June 01, 2017, 03:49:12 pm »
If It had gas leakage out before ,It must be bad now ,do not trust    the result of chinese tester.It just a toy
 


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