How to Measure Capacitance without Desoldering Capacitors from a PCB

[@BPToneReview]

I came here to learn how to measure caps without desoldering…..still waiting

[@bobisyouruncle1]

With an 100khz esr meter outputting less than 0.5v(to not switch on surrounding active components), you can test the esr. For 10uf and higher, even with a 2ohm resistor across the cap; if the reading is higher than 1ohm, the cap is suspect.

[@cougar1861]

At 13:14 Mr ToolBoom clearly states: "In this video I have shown you that measuring capacitance without desoldering capacitors from a PCB is a myth"

[@BPToneReview]

@@cougar1861misleading title

[@velimattiollilainen]

don't hold your breath

[@iankelly694]

I'm a total novice, just developing an interest in electronics, I was wondering why my results measuring capacitors in a PCB were so weird, and this video taught me why. thank you very much.

[@qkitselectronics5415]

I have done repairs for 40 years + do you know how many people have told me I do not have to remove the part to measure its value? More then I can count. I will just send them right to this video in future. Great video! Just great.

[@ToolBoomVideo]

Thank you! We are glad that we helped you!

[@tubee2b]

@@ToolBoomVideo Your assertion that no other method works for testing capacitors may very well be accurate, however, your omission of any other method in your demonstration does not help in proving that assertion. It actually was a waste of my time.

[@NyomanSuryasa]

Can you advice how to this technique, for measure capasitance broken or not, and how to measure number for capasitance, because capasitance type smd not have value in body, and when the broken cut like burn, no have resistance value. 🙏🙏🙏

[@gordthor5351]

To tell people not to buy an ESR meter is plain bad advice. When a capacitor goes bad it is WAY out of spec (you don't need super accurate measurements)and most often the reason why a circuit failed. For quick troubleshooting an ESR meter is priceless.

[@Lyzzzander]

Most of the times electrolytic caps looses about 20-30% of capacitance with increased ESR, and for most applications even cheap chinese transistor-tester tool is enough.

[@clems6989]

Exactly right, an ESR meter is essential to troubleshooting. And you cant measure capacitance in circuit. Yoyr measuring more than just the capacitor. Often these caps are in parallel so, your measuring two caps etc..

[@jonfreeman9682]

@@clems6989 So what's the alternative? Alot of PCBs have hundreds of caps. You can't exactly de-solder each one as there's too many and you make a mess of it. So how can you check for bad caps in circuit? Not really concerned with the measurement but just which one is dead or malfunctioning. You can have a good reading but the cap could be dead. So any alternatives?

[@clems6989]

@@jonfreeman9682 Thats where an ESR meter comes in. It can measure in circuit. And if the Electrolytic cap goes bad, the esr will increase (a lot.)

[@jonfreeman9682]

@@clems6989 Okay I'll order one to give it a shot. I'm trying to fix a TV and there's hundreds maybe thousands of caps and it's not practical to de-solder each one. An in circuit tester would be helpful. Don't care about measuring capacitance but just wanna know which one is dead and needs replacement. Thanks.

[@forsale313]

Thank you for confirming the common sense rule that I learned 40 yrs ago in High School, You Cannot measure the capacitor while it is ON the Board (No matter what You use)!

[@cruise2023]

Hi! Okay can I ask how do you measure a capacitor in circuit on a non pcb board ? I have just built a speaker system where one speaker is fine the other the tweeter and mid range has no sound. The crossover is dedicated to the tweeter and mid, the woofer has its own. I have checked all, the drivers with a multimeter, they are fine, drivers hooked up directly to wiring of the binding posts, all good. Once hooked up to the crossover, nothing. The crossover is identical to the one in the speaker that works, have checked, have checked, it looks fine, everything fares out. I am left with is there something wrong with the crossover ? Hence I want to check the caps ( high end caps ) they are of course soldered in place and glued to the ply board. How can I measure each cap to see if one is dead ( long shot as they are new ) Another question if there is a dead cap in place would that stop the current flow, hence no sound or would it go through and mess with the sound ? Sorry for the long story, I am fed up trying to sort it out, I need help... thanks Alain

[@ZilogBob]

It is *not* the capacitance which usually degrades. It is the Equivalent Series Resistance.

[@Drfine22]

Yes

[@josephleecanton949]

If you wish to test a capacitor without removing from the PCB maybe it would be better to test with a device intended to test a capacitor in place. I don't think this multimeter is intended to test in place.

[@jonfreeman9682]

So what device would that be?

[@irishguy200007]

ESR meter?

[@DavidParker-i8o]

ESR meters use a 100 KHz sine wave, as to not activate other components when tested "in circuit". And is still a valuable tool for testing them. However a capacitance tester is also a good tool also. But does not measure "leakage", which requires another tester, especially for electrolytic capacitors. So, it's not easy to determine if a capacitor is actually good or bad.

[@ToolBoomVideo]

You are right, therefore, certain rules for measuring components must be followed.

[@zedbear1]

I'm just getting started learning about circuits and tests. I appreciate your advice and proof, You saved me $60.

[@abasoul]

If you suspect that you have a defective power supplies and you only have a few capacitors....then just "recap" the unit. If the unit works...then problem solved...if it still does not work then double check your work to make sure you've replaced the caps properly ( verify value and polarity. If everything is OK then go on to further diagnosis!

[@irfanmkws]

We can't measure capacitance inside circuit but we can measure ESR in circuit with MESR-100 which is good enough to troubleshoot any circuit dead because of a capacitor

[@cotto887]

but with a mesr100 you get an accurate measurement that tells you that the capacitor is bad.

[@izzzzzz6]

@@cotto887 What do you mean "but" you are almost saying what he said. is that a question without a question mark? You might be able to find bad caps with the mesr100 but it is still best to take them out of circuit to double check. A capacitor needs to be checked with the correct frequency depending on it's value. the mesr100 uses 100khz which is good enough to give you a rough idea for most caps. but if there are more than one capacitor in parallel you need to take that into consideration. Try borrowing one and checking esr values when you put different voltage and different values in parallel. If the circuit needs to see an esr of a certain value them you may want to experiment with capacitor combinations to get a really good value. Some of the cheaper caps from asia might not have the esr you are expecting to see but sometimes you might be able to improve the esr value by mixing 2 new caps in parallel to make up the replacement part..

[@jonfreeman9682]

That's all I wanna know. Is the cap bad or not. So this tool works to find bad caps?

[@irfanmkws]

@@jonfreeman9682 Yes exactly

[@jonfreeman9682]

@@irfanmkws Okay thanks. I'm gunna order one to test it out. It's just not practical to de-solder hundreds of caps to test each one.

[@johntube2525]

Just a guess, but I am guessing you do not own an ESR. Would have been a better video had you checked all of them including where one did not exist with an ESR. Especially the last one which appears, based on Capacitance reading out of circuit, to be a bad cap. Show the same in circuit test with ESR and out of circuit test with ESR, then conclude. I do not currently own an ESR and I am for sure a nooby. Was that circuit board bad, not working? Perhaps only not working because you removed a cap? Did you replace that last cap and the missing cap and put it back in service?

[@fins59]

Misleading title.

[@billgates3699]

Saved me 13 minutes 😮‍💨

[@robburnquist]

I love it! It stopped me from troubleshooting incorrectly and doing things the right way, cuz there is no way I’m paying for this customers pcb out of my own pocket 😂

[@jj74qformerlyjailbreak3]

To test Caps in Circuit I use Diode Mode. If any electrolytic stay shorted then I’ll remove it and test it. Usually easy to find the fault. However I am learning myself.

[@jonfreeman9682]

Can you explain how this works.

[@jj74qformerlyjailbreak3]

@@jonfreeman9682 if the cap your testing takes charge, swap the leads and do it again. When you swap the leads the cap will discharge showing a short for a spit second and recharge. Swap them again the same thing will happen. Like my comment said I’m no expert but this got me for a while.

[@jonfreeman9682]

@@jj74qformerlyjailbreak3 That sounds like it might work. So I use the diode test to charge it up then switch the leads to see if it sparks to short it out. This proves the cap is holding its charge. A bad cap would not hold its charge so it doesn't spark. Ok I'll give it a try. Thanks for the tip.

[@jonfreeman9682]

@@jj74qformerlyjailbreak3 That's really all I'm after to find the bad cap. There may be under performing caps that still hold a charge but may not be up to spec but I think most caps either work or don't and the circuit should be designed well enough that there's tolerance for caps a little out of spec. So the goal is to find the really bad caps that don't work at all.

[@jj74qformerlyjailbreak3]

@@jonfreeman9682 sometimes it’s best to replace all electrolytic caps. Even this method only takes you so far.

[@maxwarfield6699]

I’m working on a synthesizer that doesn’t work. This thing has easily more than a hundred electrolytic capacitors, which don’t look damaged or swollen - are you suggesting that I remove every single one from the PCB, when I could use an ESR meter and get “maybe not the most accurate” measurements, which will get me a rough idea of which capacitor, is causing the problem?

[@motleypixel]

I'm not saying you should remove all of them, but yeah, good ESR should be a go-no-go test to replace or not replace a cap w/o having to spend a load of time removing/installing caps.

[@gbennett58]

Keysignt U1733C Handheld LCR Meter also measures ESR, so yes, these meters are made by well-known instrument companies. Keysight is comparable to Tektronix, Fluke, etc. any day.

[@frundlemud]

Excellent explanations of how not to test caps and the correct way. Thanks.

[@Arek_R.]

Omg I expected trick that let us measure it... To determine if capacitor is damaged, w/o desoldering, we can measure ESR with appropiate device.

[@Arek_R.]

@Mason Troy Whoa! It took me 1 second to realise you two are fucking scammers!

[@jonfreeman9682]

So after 6 years have you found a way to do it yet? Please share.

[@Real46]

It is possible do measure capacitors on the PCB. You just have to cut the traces near the capacitor or desolder and remove every other components from the board. Notice that for the second capacitor, you don't have to put all components back, just remove the first and put the second in its place. However, I don't know if it works for flux capacitors.

[@ToolBoomVideo]

Hello! Thanks for the great and detailed comment!

[@jonfreeman9682]

Excellent tutorial. That's what I suspected all along but now you've proven it. Great job.

[@InssiAjaton]

There are two situations to consider. First, are several capacitors DIRECTLY in parallel. Second are there one or more resistors or chokes separating the multiple capacitors. These are the very basic two configurations. You can complicate the conditions to any degree, but to really see what happens, start with simplest reasonable things that the school formulas can handle. For example, take just one capacitor and one resistor in PARALLEL. A normal DMM with a capacitance measurement capability probably works by charging the component (assumed plain capacitance) and discharges it, then calculates the “capacitance” from its known charging and discharging currents AND measured times, say between 0 and 1 V. Fine, without the actual additional resistor. But that resistor slows down the charging time and speeds up the discharge time. Moreover, both ramps are not linear any more - you are now dealing with exponentials. But here is a little secret: The true LCR meters use AC bridges (or similar). You can get both capacitance and resistance readings, when you balance the bridge. That is the basic trick. But you can go further by doing a little math. You can get the capacitor reading ALONG with the Q-factor on for example with DER EE model DE-5000. It allows measurements at 100, 120, 1000, 10k and 100k Hz frequencies. You can (don’t you?) calculate the components from 2 or more measurements at appropriately selected measurement frequency pairs. And another little trick to remember - your DMM can measure the DC resistance without any effect from the capacitor, if you wait long enough, that is. Then you can analyze the RC circuit. I myself can often see enough of the component connection effects even in more complicated leakage paths, when I measure 2 or 3 frequencies C and Q. Or L and Q for that matter. And finally L and C. All by utilizing just simple reasoning or in case of more complicated interactions, plotting the results in a graph. By the way, I have made a handy log-log graph impedances versus frequency of both various (decade) inductance and a capacitance values on the same chart. The resonances appear where the appropriate value lines cross. 10 or 100 times faster than using a calculator.

[@shlomoattia7706]

i think that you should test with ESR and then see? why didn’t you test it with ESR ? thank you for your time and effort 👍

[@ghislainriou9560]

Thank you sooooooo much for this video fantastic explanation to the point. Question how would you measure ceramic SMD caps on the PCB and a fluxe 87V RMS multimeter will it do the job. if you can make a video of the ceramic SMD capacitors test many thanks in advance.

[@peckelhaze6934]

At the start I thought you had discovered a multimeter to accurately measure capacitance in circuit. This went against all that I know so I am pleased that your tests prove my assumption right. A very good test.

[@irishguy200007]

The title was missleading

[@bobisyouruncle1]

Yes, false advertisement

[@marks6292]

Well, let me say that I was on the hunt for an in circuit ESR Capacitance tester. Not any more. I thought maybe the technology had improved in some way. Interestingly, B&K sells one of these. A company that was usually well respected. Its obvious that the best way to find a suspected problem capacitor is to understand the operation of the circuit it is installed in. Then, once you narrow down the basic area, you can surmise which component may be causing the problem. It would seem that good analytical and technical troubleshooting skills are still a must.

[@losthor1zon]

ESR can tell you if a capacitor is out of spec. It won't give you accuracy, but will help you troubleshoot.

[@cotto887]

the capacitor when it is bad is bulged.when shorted not bulged.esr is accrurate enough

[@kilgoretrout4461]

ESR meter is an invaluable tool. Doesn’t have to be perfectly accurate. It’s well accurate enough.

[@izzzzzz6]

@@cotto887 lol, not always. Not that often.

[@jonfreeman9682]

@@kilgoretrout4461 Did you try it out. Does it work in circuit to hunt down bad caps? If it works I'll buy one.

[@thefifthdoctor6780]

I got an ESR capacitor analyser

[@VictorLee335]

I first thought it was a video showing how to measure capacitance without desoldering caps...

[@charlestaylor6928]

Victor Lee hi

[@fejneerg]

That's what I thought. What a jerk.

[@alfricko]

He wasted my time

[@Roadsurfer2k11]

I was thinking, his poor wife has to listen to him talk like that 24/7. "As you can see, I'm firmly planted in my chair with my soda pop, consistently chilled to 7 ice cubes. And the value of its contents is 6.8 ounces. I now have an adjustment as I just took a sip"

[@tarseal1]

i noticed you never discharged any capacitor before you tested it on the PCB. just saying.

[@xavier_sb]

He may have done it during the cutaway at 6:12. Although he never mentioned anything about it, so it's impossible to tell.

[@cotto887]

because you did not descharge the caps . thats why the readings where not accurate

[@LenoreMaggs]

I found the easiest way to measure caps is to cut at least one circuit track, then measure the components leads, once a reading is made, scrape the cut track to expose the copper from under the gel coat, tin the exposed tracks with a light coat of flux solder, you'll need to make a new trace using tinned copper wire, once a replacement track is made, the capacitor will receive its full electrical current, / note: keep your soldering iron tip tinned at all times with good quality solder, Kester makes the best

[@NyomanSuryasa]

But, if not measure with desoldering, how to the measure, capasitor smd without simbol or number in the body, but this capasitor short or cut. How to the identification capasitance for this problem?

[@colindiggle9377]

thanks so much mr boom just bought a new meter like yours had no idea what to do im going try it now with your help brill thanks we all need to work together with help xxxx

[@arsinoeivlostprincess4228]

Thanks, I watched several before yours and yours was the most understandable.

[@ToolBoomVideo]

Thank you, we are very glad that you liked it

[@nonsuch]

My LCR meter does a great job of measuring capacitors in-circuit. However, I primarily use it for non SMD components as for I don't work with them. But I get the same result with the meter when I measure capacitors in or out of circuit. So, they do work. And for the record, ALL the major brands make an LCR meter. A standard multimeter will NOT work.

[@nonsuch]

@@Leilektsoglou It was so cheap, I really had nothing to lose. To my suprise, it measured caps in-circuit and measured down to 2pF!

[@nonsuch]

​@@Leilektsoglou I'm positive. If it says 18 on the cap, it measures 18 pF or so. If it says 22 on the cap, it measures 22 pF or so. It somehow even takes the capacitance of the probes out of the equation. I don't have a link to show it to you, you'll just have to trust me on that. For a $20 LCR meter, I was shocked and overly pleased. It also does inductors over 20 H which is large. I mean, don't expect a meter that cost over $100 but for what it does and the results I get, it's been worth every penny in my opinion.

[@nonsuch]

@@LeilektsoglouAnd believe me, nowhere in the specs does it say you can test capacitors in-circuit or test them down to 2pF, it just does. I would buy it just for those 2 things alone if that's all it did. And I would pay a LOT more for it. It sounds too good to be true but, I'm not lying.

[@imatus235]

@@nonsuch Does it measure ESR aswell? And you mean theseone from Ali??

[@bobisyouruncle1]

With an 100khz esr meter outputting less than 0.5v(to not switch on surrounding active components), you can test the esr. For electrolytics, 10uf and higher, even with a 2ohm resistor across the cap; if the reading is higher than 1ohm, the cap is suspect.

[@trickedouttech321]

OK! I like the video and everything is 85% correct except when you mentioned the word ESR along with capacitance measurements. Oh, and the part of big name companies. 1st ESR (Equivalent Series Resistance) I don't see the word capacitance in ESR anywhere? ESR measures Equivalent (Series) Resistance and can measure this (in a circuit)However there are situations when it can't, This is all fact even without going to Tech (school) as you put it. 2nd: big names. Agilent/Keysight, BK Precision, Instek These are all big names some bigger than other and some are about as big as it gets, I'm leaving many out. However, some of the big brands are adding the functionality to their LCR meters Making them LCR/ESR meters. Again your pretty spot on, when it comes to capacitance in a circuit. Now let us go back to that same school you were talking about. I'm sure you will remember something about capacitance values along with what happens when the value of a capacitor starts to drop, No matter why, time, voltage or damage. Remember what happens? As capacitance value drops (resistance value increases) WHAAAT? So, you mean to tell me somehow if you could measure the resistance of a CAP (in a circuit) he'll I don't know maybe with something low like 100Khz or less, that you could tell if a CAP was good or bad. Just by, if the resistance was within spec? And not even check the capacitance? Well, yes I believe that is what I'm saying, "it's called an ESR meter". They have been around for a long time now. I know this post is older, sometimes I can't help myself! While reading remember I am (not) claiming his entire video is wrong just a little one sided is all! Thanks for reading. Hope you enjoyed whether you agree or not, sorry for any spelling errors am in a hurry!

[@danishdart]

The uni-t 139c is not very accurate for measuring capacitence nor is any other DMM in my experience. Perhaps in the ranges 1-1000 micro farad it's okay. But below or above that range, a DMM becomes slow and/or inaccurate. I measured only yesterday a 4700 uf capacitor with the uni-t 139c. It gave a reading of 4300 uf compared to a honeytek A6013L meter which gave 4680 uf reading. Which on do you think is correct? As for measuring a capacitor in circuit it is hardly worth debating. Of course you can't measure a capacitor in circuit with a DMM. The circuit affects the reading. However, with an oscilloscope and function generator and a bit of math you can! But it's probably easier just desoldering the part and measuring it.

[@wolo]

Note the video is about explaining the method, the idea. It's not about this particular multimeter/brand/accuracy problems, guy said this one works ok for him, if someone has better one, needs better accuracy, what stops they to just use it. Even if Unit is not best one for building space rockets, it's clearly quite enough to detect a capacitor which is clearly broken, in everyday simple hobby projects, maybe old hifi, or guitar drive pedal, you don't have to own a Fluke nor some specialized capacitor test tools for that

[@danishdart]

@@wolo I don't think you understood my reply. I'm saying that almost all digital multimeters are bad at measuring capacitors. Especially relative to how great they generally are at measuring voltage and resistance. Can't speak for fluke because I don't own one but for accurate measurements of capacitors you would need an LCR meter or a meter dedicated specifically to capacitors. In addition to that an ESR meter is needed as well. Just because a capacitor measures to spec in capacitance doesn't mean it can't be failing in ESR. Edit.. Just rewatched the video. At the end of the video where he says to trust the DMM over an LCR Meter or an ESR meter is just false. You can't measure ESR in circuit the same as with capacitance so you have to remove the part from circuit to measure it. For the record I own a 8 different DMM's All of them are not accurate for capacitance except my siglent SDM3055 which is an expensive bench meter.

[@wolo]

​@@danishdart What I meant in short - that such capacitor specialized testers are owned mainly by advanced and professionals, and such knows these tricks already, but normal everyday enthusiasts with some of knowledge and some of tools usually don't own them. I can count 20 or 30 of my people, who has various class multimeters, at least minimum soldering skills, and was able to bring at least one broken device of any kind back to life, as far I know them. And I'm pretty sure, maybe 2 or 3 of them I can suspect possesion of such device like specialized capacitor esr meter etc. It's just not very common tool on hobby level. I personally, use the known aliexpress diy transistor tester tool/toy kit, but it won't be surprise to me if that thing measures them even worse, but tbh never compared results of mine to anything

[@igrewold]

Thanks dude, but I think you should discharge caps before measuring them by shorting their legs with any metal object like a jumper cable for a coupla seconds.

[@andken62]

Actually if you noticed the board was not powered or energized for quite some time, in that case there would not be the Beed to discharge the capacitor.

[@Milkex]

This video makes me feel uneasy. Liked!

[@Appregator]

Do you have the circuit diagram of the front end of that UNi-T capacitance section of that meter. I have one and it measures about half capacitance and inductance for everything. Haven't figured out the fault yet. I seems to have a 7555 driving oscillations which is OK but think the fault is elsewhere.

[@coatbridgedrivinglessons8106]

Just finishing an hnc in electrical engineering and been told to always remove from board to test capacitor. one quick question on capacitor 6 where there was a 35% variation in the reading would you consider that capacitor as faulty. what would you say is an acceptable tolerance? thanks for the video.

[@ToolBoomVideo]

Hello! In this video, we wanted to demonstrate how the multimeter readings differ when measuring the capacitor's capacitance on board, and when measuring the same capacitor, soldered from the board. Measurements showed that the capacity of one of the capacitors was significantly different from the nominal. Obviously, it was damaged. Since the video was made a few years ago, we no longer have those board and capacitors, as well as technical documentation. Therefore, we can’t re-examine or verify it.

[@cotto887]

the tolerance for electroletic cap is 20 percent that cap is faulty

[@TheMartinH13]

So is the reading on no.6 capacitor bad enough that it needs to be replaced?

[@ToolBoomVideo]

Most likely, this indicates that the capacitor is old or on the verge of working capacity. Therefore, it is better to replace it.

[@valveman12]

Just use an ESR meter and you can find good or bad caps in circuit.

[@twoshedsjackson6478]

ESR's cannot work, thats what the video is about. That's why major multimeter makers don't sell ESR's. Watch the WHOLE video.

[@valveman12]

@@twoshedsjackson6478 I use an ESR meter all the time. Works great when measuring a capacitor's equivalent series resistance in the circuit. If your capacitor is damaged, it will show you very quickly. I use an ESR meter to make the job of finding bad caps much easier than taking each one out and testing them individually... Of course, if there is physical bulging or leaking, no meter required. Just replace the cap.

[@losthor1zon]

@@twoshedsjackson6478 - ESR helps troubleshoot because it shows quickly if a capacitor is out of spec. It won't give you accurate capacitance.

[@metalWarriorCZ]

​@@twoshedsjackson6478 in video he was measuring capacitance, nnot ESR. This is a huge difference.

[@Appregator]

@@losthor1zon You don't measure capacitance with an ESR meter.

[@renegademind1833]

Geeze.. I'm still @@ mind boggled, I'm clearly outta my league. Thanks for the video

[@ToolBoomVideo]

Hello! We're glad you liked our videos. Stay tuned!

[@irishguy200007]

What about if you're checking for shorts? It's possible to check in circuit accuratly enough?

[@ToolBoomVideo]

Measurements using this method are quite accurate.

[@mobilered2776]

Hi, plz suggest me which Meters is good and best to use True RMS , Fluke is very very expensive, I need next player in market .

[@ToolBoomVideo]

We suggest that you pick up a True RMS multimeter from UNI-T, which offers reasonably good performance while being considerably cheaper than FLUKE products. You can find and compare UNI-T True RMS multimeters in our store: toolboom.com/en/catalogue/test-and-measuring-equipment/multimeters/?brand=uni-t&properties=3300

[@RixtronixLAB]

Cool video shot, thanks for sharing it with us, well done :)

[@VashStarwind]

Is it possible to lift just one leg of the capacitor out of circuit then test? Or would that also give you false readings?

[@nageshji8771]

multimeter just applies 12v under room temperature to read value but real life a power capacitor turns out different in circuit under high volt current, temperature like imduction stove....aging deformation is best guess to replace capacitor

[@brianpeever2300]

Great video thanks. I'm getting back into the electronics hobby and found this helpful.

[@longtimegaming1080p]

Very misleading title. A more accurate title would be "Why it's necessary to desolder capacitors in order to get an accurate reading."

[@perryjones8997]

I disagree. The title accurately examines the QUESTION asked in the title. Not misleading at all.

[@surgingcircuits6955]

Title mislead me.

[@kjaxky]

yep agreed

[@marks6292]

Not really. It proves that it cannot be done. This has saved you thousands of hours of stupidity.

[@JoeJ-8282]

Yeah, video title should have been "Proof that you cannot accurately measure capacitors in circuit" or something similar to that.

[@BillEyles]

I find it hard to believe that those caps are off that far I use a deck top multi meter tha has a capacitance test in it and have never had a different reading in or out of curcit. A good meter will induce a very low current for testing and will not upset other things in the curcit as other meters will

[@barryoliveira5527]

Title is a little misleading. I thought you were going to show a way to do it instead of showing why not to do it.

[@jimbanville]

If your point was an ESR meter isn't reliable for testing capacitors in circuit, why wouldn't you actually test that theory by using an ESR meter?? LOL. I'm going to prove wine gets you more drunk that beer by making a video drinking whiskey! Hahaha!

[@rodbhar6522]

If you get a very low capacitance reading in circuit like you did with #6 then you know the capacitor is bad because the rest of the circuit can only add capacitance not subtract it.

[@gordthor5351]

Rod Bhar Capacitances diminish in series.

[@Pootycat8359]

@@gordthor5351 At the cap's terminals, the reading will AT LEAST be the value of the capacitor. Anything connected to the terminals be in parallel, if it has a return path to the other terminal. You CAN read a lower value, if you're using an old-style bridge type tester.

[@Steamtostay]

Can the method be used to measure whether or not a capacitor is connected to the circuit on both leads, ignoring what its actual value is?

[@abeleballestri612]

Very well done the measurement of the capacitor. I think I will buy such a measurement device. Thank you for your nice adversment

[@sebidsouza4029]

What is the model number of the multimeter u were using in the test

[@ToolBoomVideo]

Hello! UNI-T UT139C (UTM1139C): toolboom.com/en/digital-multimeter-uni-t-ut139c/

[@sebidsouza4029]

@@ToolBoomVideo thanks bro

[@Drinkyoghurt]

I'm not so much interested in checking capacitance, is it possible to just check if a capacitor is OK? I currently have a project with over 100 caps that I need to check/replace and it would save a lot of time.

[@jonfreeman9682]

That's what I'm trying to figure out. There are hundreds if not thousands of caps. How can you test without de-solder everything?

[@miroslawkaras7710]

I do not think that using LCR meter with ESR capability it can determin capacitace in circutit. Because you can have resirance in series or prrallel.

[@discoHR]

I've purchased UT-139B the other day and I like it a lot. Where can I buy compatible mini aligator clip probes, like these in the video but with a bit longer cable?

[@igrewold]

www.banggood.com/SMD-Inductor-Test-Meter-Clip-Probe-for-Resistor-Capacitor-Multimeter-p-912618.html www.banggood.com/6Pcs-Multimeter-Lead-Wire-Kit-SMD-IC-Hook-Test-Clip-Probes-Cable-p-930562.html

[@cotto887]

amazon

[@claesmansson9070]

An esr meter sends a wave, normally 100 kHz through from measuring point to meas. point., how accurate it is I don t know, cause I haven t received my DE 5000 yet, thank you.

[@68camaroblue]

Thank you! What a great video!

[@mrcelada]

It is better to use an ESR meter? Does a fluke 115 work in a similar way or it is better?

[@dalesworld1308]

So you desoldered a lot of good caps and now the leads are so short they can't be resoldered back to the board? I couldn't anyway, my eyes and dexterity ware waning.

[@ToolBoomVideo]

We did this for demonstration purposes. However, if you try very hard, then it is quite possible. :)

[@kjaxky]

You've in no way shown anything, even though you started put badmouthing ESR meters, except that a multimeter is only a good tool when caps are desoldered. dozens of experienced techs incl tampatec and Mr. Carlson have shown that esr meters work.peehaps you've not a good understanding of esr, lcr and multimeter with capacitance testing. there's even a Austrian tech who shows in great detail why and how all 3 work and how to use them properly. major MFG don't make? so what? major phone MFG didn't make smartphones either till android came along. or home computers till Apple, major MFG don't make sound cards till creative Labs, they also don't make magic jack, or usa fta set top boxes, etc etc doesn't mean they don't work. if we all had to rely on and only trust major MFG then only electronics MFG would be requiring electronics. a major MFG is like a elephant, not nimble. introducing a new product line is hard for them.

[@firstman9273]

Can you give the channel name of the Austrian guy? or any others who show how to use ESR effectively?

[@dlcarburetor]

This is a great video that helps me save a lot of time that I would have wasted testing in circuit. Thanks. This video verified what I thought

[@ToolBoomVideo]

Thank you! We are happy to be of service to you!

[@mayurkakade4327]

How to find smd capacitor voltage Value??

[@ToolBoomVideo]

Hello! Smd capacitor voltage Value You can find in the device datasheet.

[@JUANTAMAY]

Thanks for the information!

[@brianwalker7771]

I have seen people clip on to a capacitor on board claiming to be an accurate test. I am learning about this stuff little by little and my knowledge base on available equipment is extremely limited so please bare with me here. Would a tester with a specific clip type work for on board reading IF the clips caused a temporary circuit interruption? Thus effectively removing the capacitor from the board while it is still attached.

[@masoudmontazery907]

Good luck sir 🎉

[@jameswallace5967]

This is why they invented the ESR meter...

[@greywolf271]

There was nothing to invent. Circuit analysis has always considered equivalent series resistance when needed. It always has been a simple impedance measurement in the old days when electronics and especially RF circuits did not need to go into the SHF spectrum. However nowdays its very important in circuit design

[@Hamradio54730]

Your approach is unfounded. Esr meter is always the go to. Your theory is misleading.

[@Albertojedi]

Don't you have to first discharge the capacitor by connecting a resistor across the leads?

[@ToolBoomVideo]

Good point, you're right - it's worth discharging the capacitors before testing. In our case, they were obviously discharged.

[@GSBrigida]

You could cut a fairly large piece of unnecessary video footage, stringing together a much more bearable video to watch

[@ributrax1]

Just an observation why are you not measuring the capacitors with its correct polarity meaning black wire to negative and red wire to positive? Does the Uni-T UT139C measure electrolytic capacitors that way?

[@ToolBoomVideo]

In this case the polarity does not affect the measurement result.

[@underdog576967]

How about using an in circuit measurement tool to compare ? Watched the video which was misleading

[@ToolBoomVideo]

For in-circuit measurements, you may want to consider BOKAR ST-5-S smart tweezers, which are a combination of a digital multimeter with a high precision SMD probe. Look it up here: toolboom.com/en/rlc-meter-bokar-smart-tweezers-st-5-s/

[@ruialexandre6197]

Summing up the video: Measuring capacitance without desoldering capacitors from a PCB is not possible even with "special", non-official instruments. Explained in the movie why.

[@os-qt1hc]

one of my capacitors measures OL on pcb, but when i desolder it and measure it, it is ok.. around 100uF ... i am trying to find out what is wrong with a monitor that won't turn on.. this is some tough shit for me.. i don't know what to do..

[@ToolBoomVideo]

Hello! Try replacing this capacitor with a new one. If your monitor doesn't work, the cause of the malfunction doesn't relate to this capacitor.

[@Mink-rz6vs]

@@ToolBoomVideo Maybe if he's lucky, but that's time consuming and poor repair advice. Anyone doing that for all the E-Caps on a board will go out of business doing repair, and possibly blow a new cap. An ESR meter will check for BAD capacitors on PCB (one doesn't need to measure CAPACITANCE to find BAD caps. Also check diodes and transistor junctions in the power supply section.

[@SteveM45]

What about RCL Meter?

[@Podcast_me_Riatin]

Thank you sir..I was about to buy ESR but now I changed my mind.

[@ToolBoomVideo]

Hello! We are glad that our video helped you! Subscribe to our channel, there will be many interesting videos and reviews!

[@oldspiced]

not sure how i feel about this clickbait XD

[@colin7406]

2:11 WHY did you set a circuit board on a static paper

[@ToolBoomVideo]

Hello! Thank you for your comment. However, in our case, this does not significantly affect the measurement result.

[@freemanhickey7047]

But electricity will follow the path of least resistance, just because you put the probes on the capacitor doesn't mean your test will on run through the capacitor of there is another path of less resistance electricity will flow that way or there may be other components in parallel or series it's not accurate test

[@bobross6802]

The best instrument for testing capacitors is a curve tracer !!

[@daytonagreg8765]

Excellent

[@MrMr123]

I like this guy 😂 no bs

[@robh1908]

You couldn't pay me to use Uni-T Horrible build quality. Check the reviews and teardowns, they are absolutely garbage.

[@mdhsabh]

If I saw a technical presentation that abbreviated Hertz as Htz, I would wonder if the presenter had any formal, practical or academic familiarity with the topic. Same here, seeing uF (microfarads) abbreviated Mk"phi".

[@ToolBoomVideo]

Hello. We apologize for this inaccuracy. The fact is that on paper "мкФ" are written in Cyrillic, which also means μF. (And "мФ"= "mF")

[@JMLRecording]

This video is giving bad information touted with a misleading title. Title should then have read, "Why it is NOT possible to measure capacitance without desoldering capacitors from a pcb. And btw, ESR meters work totally fine to check for bad caps.

[@nunyabusiness6746]

joshua lutz Wr

[@stevenw4549]

You say it can't be done when I've seen it done. Not perfect readings but more then good enough to find bad caps.

[@ToolBoomVideo]

Hello! Our video is aimed to show that it is incorrect to measure the component parameters on a PCB without desoldering them.

[@stevenw4549]

my point is however incorrect it is using an esr tells you if cap is bad or not without taking the cap off the board. also you used a cap meter which we already know doesn't work. you should have used an esr and prove they don't work that way. your test was not relevant.

[@jimcabana9309]

Steven Watson I was thinking the same thing. It would have been a more accurate example had he also used an ESR tester.

[@stevenw4549]

@@jimcabana9309 Great minds think alike ; )

[@Mink-rz6vs]

@@stevenw4549 Exactly. This issue is: is the cap good or bad, which ESR will usually tell you. Electrolytics go large when they go.

[@JUANKERR2000]

Interesting but what is that infuriating background noise?

[@wh0tube]

Imagine if in order to measure a patient’s temperature you had to first unplug them!

[@KoolBreeze420]

I thought as much but having it confirmed is good so I don't waste money on my next meter.

[@eberhardhewicker8474]

Title is misleading, yes! Micro-Farad is by no means abbreviated " Mkphi"! it is µF!

[@klannstyle]

It's in russian i think. If it was chinese you will see their language, so... it's not about abbreviation

[@franb3352]

This demonstration shows nothing! What is your point?

[@ToolBoomVideo]

Hello! This video shows you can't measure the capacitance of the capacitor while it's on the board. In order to do this, you need to solder it out of the board, and then you'll be able to measure its capacity.

[@tubee2b]

Exactly!

[@aurellioroccone2150]

Cannot measure capitacince on pcb so what gives

[@Americal1970]

I agree.

[@RussellTeapot]

First of all, excellent demonstration. Secondly, I didn't even know such magical on-board measurement devices even existed, yet alone people could fall for it. I'm a beginner, but the theoretical reason you pointed out why such devices can't possibly work is something I learned very early: after being introduced to Ohm's law, it was demonstrated how resistors connected in series or in parallel can be simplified into a single equivalent resistance, and effectively they look like a single one from an external point of view (either a power supply or a measurement tool). Later it was further clarified how and why the different formulas are used, by leveraging on Kirchoff's laws, and it became very clear that it stems from how voltage and current are distributed by the different nature of the connection (series or parallel). While messing around with a couple of resistors on a breadboard to get a feel of how to test things with the multimeter, I was puzzled why I was reading a different resistance on a specific resistor which was perfectly fine when measured alone, then realized that other resistors were connected to it in parallel: it was a very "Ohhhh, now I see, silly me" moment for me :D Obviously the same holds true for any other passive component: capacitors and inductors can be treated as equivalent capacitances or equivalent inductances. Sometimes we have huge brainfarts moment (especially when you are starting to learn a new skill), I do aswell, but it baffles me how someone could buy such magical devices, and makes me question if they are able to use a plain old multimeter in the first place

[@ToolBoomVideo]

Hello! Thank you for such a great review. Totally agree with you. :)