I was wondering: if you remove a capacitor from a circuit, you test its ESR and it seems fine for its stated capacitance, does it mean the capacitor is fine? Would an additional capacitance test be relevant? I'm asking this because I'm already using an ESR meter, my multimeter doesn't test capacitors, and I was wondering if an additional capacitance meter/multimeter would be worth the investment for hobby repairs. Does the ESR test (out of circuit) make the capacitance test obsolete? Sorry if it's a stupid question, I'm a beginner.
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Last edited by cib3k; 11-04-2013, 03:30 PM. -
Re: Is testing ESR enough?
And just to be clear: I know that ESR and capacitance are different things, and that ESR can be measured in circuit.
Also, another question: why do most multimeters that measure capacitance only go as high as 20uF-200uF? I've seen 2200uF electrolytics in PSUs and 3300uF on motherboards, so higher capacitances are pretty common. Is there a problem with accuracy, maybe?Last edited by cib3k; 11-04-2013, 05:04 PM. -
Re: Is testing ESR enough?
Hmmmm ... according to Fluke's DMM Selector Guide, almost all of their current DMMs that can measure capacitance can measure up to 10,000uF (just one is limited to 9,999uF), and some up to 100,000uF. Some of Extech's DMMs in the EX500 series are limited to 100uF, but some go up to 10,000uF; their EX400 series are limited to 100uF; their EX330 is limited to 200uF; their EX230 to 100uF; their MM500 and MP500 series are limited to 9,999uF; their MG300 series DMM-insulation testers are limited to 40,000uF. Agilent's U123X, U124X and U127X DMMs are limited to 10,000uF; Agilent's U125X DMMs are limited to 100,000uF. I realize Fluke and Agilent are pricey (don't go buying a Fluke 287 or an Agilent U1253 unless you really need that quality and capability level!); Extech's better DMMs are better in that respect without being cheap crap, though a little less capable.PeteS in CA
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Re: Is testing ESR enough?
Multimeter s perform capacitance measurements at very low test frequency of few Hz.
Therefore they are worthless for Very low ESR capacitors which require 1KHz or higher as test frequency so to be calculated all parameters as Q / ESR / Capacitance.
In conclusion anything less than a complete LCR bridge is a toy.Comment
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Hi is there a guide in this forum on how to test the LED backlight TV strips? I purchased an LED tester on amazon, but I am a bit confused on the test points and how to test the individual LEDs? I took apart a RCA 43" TV Rlded4331b. Please see attached pictures. I understand that all the LEDs are in series, but on these strips I don't see any individual test points for each LED? Any tips or guides?
Thanks in advance... -
Hello
I have power adaptor(220V/input, 12V 1.2A/output) which has symptom of fluctuating output DC voltage between 11.5V-12.2V.
So I opened its plastic case and when switched it on, I heard constant tik tik sound from inside its PCB.
I measured DC voltage between negative and positive pin of the largest capacitor(400v 10uf) and it was measured contant 300V.
I also measured ESR value of all capacitors and I noticed that one of capacitor(KMG 16v 470uf), which located in the secondary side, have high ESR value(10 ohm),So I replaced it with same specification NXH capacitor.... -
I read EBOOK of Testing Electronic Component and found that
"In order to test the small blue resin coated ceramic disk capacitor which has 104 50v specification,it is possible to test this small ceramic capacitor by making use of analogue meter.
Set to times 10Kohm that has 12v output from the probe to check disorder of ceramic capacitor.
It is not uncommon that testing result of digital capacitance meter is okay,But It show shorted reading when you check it with analogue meter."
Is it really possible to test small ceramic disc capacitor with analogue... -
Hello
I have a big problem and that is that in some cases when repairing active pfc power supplies I cannot work with a test lamp. I can only get help with 5 volts standby and for starting and starting I have to work without a lamp and this way there is a possibility of parts exploding and other parts being added.
Sometimes with a multimeter test the problems can be reduced to some extent, but I had several cases that had to be tested on and online and recently two varistors exploded. They had terrible resistance because the power supplies were over 800 watts.
Is there a way... -
Hello.
GPU came in, green lines. Spent lots of time using to get the Mats / mods drive working (found on youtube).
Found issue with a RAM block
Replaced, green lines gone.
Trying to test again, assuming getting the false positive. Originally had over 1K on a single bank. Now getting tosses low between banks.
Used a good card to test and same results low errors 32+.
I am just search for some form of command to do a full test on the GPU.
I just ran the mats command with my good GPU and passed after roughly 40 min.
The repaired one, ran...
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