Easy Electrolytic Capacitor Replacement & Testing Methods 

I helped an old friend of the family remove a stuck disc from a dvd player. I did it through brute force though as he was chucking the player due to water damage. The disc was backdoor babes 5. Awkward moment never to be mentioned outside the anonymity of the internet.

Thank you for supporting “right to repair” and less waste in the world.

describing the electrolyte leak as "shit staining" just earned a subscribe.

I always like to remind and / or teach people before touching a circuit board to confirm that the capacitors are drained first, and if not, to drain them first. Also, I love that disordering tool!! Thank you for this video!!!

I love that desoldering tool! For the record, I have been finding that most overseas manufacturers are using capacitors with voltage ratings right on the line. In nearly every instance, products that have failed me were easily repaired by replacing the caps and doing so with the next higher voltage rating available. The two most expensive items I have repaired were so very cheap to fix. First was the first flat screen TV I ever had that was a plasma TV. Absolutely wonderful image and it started to not want to turn on. Finally, I hear *POP* one day and smell the unmistakable odor of a capacitor gone bad. The TV was dead. Now, as an aside, I used to hear ALL THE TIME about plasma TV failures and how they would go into dumpsters. I opened mine up (about two thousand screws later) and looked at the power board and saw a few bulged caps and one clearly burst. Now, here's the STUPID part. Though they had caps rated exactly for the voltage of the board, the board was drawn to accept LARGER ones. "This is TOO easy!" I said to myself. Yes, it was that easy. I didn't just replace the bad ones; I replaced ALL of them for about $12. That was over two decades ago, and that Plasma set still works like new!!! Like I said, how many plasmas were trashed for a $12 fix!?!? The second item was the control board for our $1 Jacuzzi (yes, $1 from a friend that moved and couldn't take it (6 people too!). That board was a little less obvious. I found the testing procedures on-line and did everything as stated. I then found a very nice repair service in AZ that worked on them and sent the fellow an e-mail and outlines all my tests. He actually CALLED me on the phone saying that he was impressed seeing somebody else who knew about everything to make the repair. He said, "you won't believe what the problem is." I answered, "The capacitors, right?" Yup, same thing and here again, I fit the next higher voltage rating caps on the board and called it good. That board never failed again, and it only cost me $8 for those (the repair guy normally got $200 if he did it, but he didn't ask for a dime just to confirm what I already knew). So, are the manufacturers purposely cutting it too close with the caps knowing they will fail so you buy a new item? Somehow, I think so.

Thanks, you've shownthe best way to diagnose and replace bad caps. Very inspiring for those who never tried this before.

One thing that I'd like to mention for more of the new persons learning electronics. Is, if you see a cap that even a little bit bulged, don't even bother testing it. JUST REPLACE IT! There's really no such thing as a "good" cap that is bulged. Sure, sometimes a bulged might test close to ok, but it's not. Sometimes, its ESR is way off and/or once in circuit and voltage applied, its capacitance changes, way out of value. Same applies to those little tin hat caps. If you see any brown stuff around/under them, don't waste time testing. Just replace.

Use an ESR meter to check all the electrolytics in circuit. Worth the money for a decent one.

Good clear vid. Thanks.

Hi ! Certainly one of the best video I saw about electrolytic capacitors, defect, repair and analysis of why and still understandable by the common man! Congratulations and thanks!

Thanks for the explanations and demonstrations. I really appreciate people like you sharing knowledge & skills, esp'y. when you're concise & efficient with the task at hand. So many ppl spend too much video time pointing out the obviously UNrelated components &/or features. "We're going to check the power supply because the red standby light doesn't come on....or is it blue? Let's seeeee........" Um no thanks, I'm troubleshooting my DVR's power, not LED colors. Move it!

Better quality caps, last longer, in my experience, nichicon kg, rubycon, Audio note, there's lots, great video👍

My uk central heating boiler started making a faint buzzing sound, then eventually stopped working at all, as the internal fan and gas and water circulating solonoids would not operate ..After a struggle Managed to eventually remove the main control PCB from its plastic mounting pegs... No transformer to isolate the mains supply! it just used a series capacitor and resistor to drop the voltage feeding a rectifier connected to a swollen 100uf,100vw electrolytic. I replaced it with a larger 220uf 220vw connected to the back of the PCB as there wasn't enough room on the component side.. I also took the opportunity to extend the wireing loom feeding the various solonoids and fan thermostat etc. So as to make it easier to work on when in place... That was five years ago! saved £250 on a new PCB board as the repair guys only replace the PCB

Good job 👍

I have found SO many failed electrolytic caps in all the repairs that I have done over many years that I replace them with a higher voltage cap, and I have never had one come back for any related problem. Thanks for sharing the video.

Great video John, I have a player just like yours and this helped a lot if I should have this problem. Thank you.

I bought a job lot of used Dell computers from a school a few years back, and in this bundle was a brand new one that worked for a minute and failed. Needless to say i was intrigued, so the first port of call was to open up the faulty one. Lo and behold half of the electrolytics were installed the wrong way round, a quick replacement af roughly half a dozen caps and all is well again. So even the big boys make mistakes.

My 2009 LENOVO M58p desktop computer was now giving me the boot loop run around. The cause turned out to be due to there being 1 defective capacitor in the PSU. However, 5 other caps also had the bulge as well. Overall, I replaced 7 capacitors. Now all is well again. Total cost was $9.55. That is a heck of a lot cheaper than buying a new PSU. Same goes for my 2010 SAMSUNG TV. Just 1 capacitor had to be replaced, which I removed from some old junk that I had floating around, and so it cost me nothing at all. And so both are still working to this day.

Your desoldering tool is amazing sir

Great vid, as always! Thank you! :)

10 points!! Ding ding ding! He can pronounce solder! Amazing!

Thanks! Have the same problem so now I know how to fix it 😬

Nice info, thank you for sharing it :)

When caps fail and get bulged i replace them with a bit higher voltage rated ones, in that case if they are 16v I put 25v if the size allows me. I use to test caps with an analog multimeter but after all this years i found the best method is replace "all" old caps for new ones especially on the hot locations on the device and the power supply.

So typical in power supplies. The capacitors are failing due to the poor selection of the capacitors in the design of the power supply. There is a spec called "ripple current", and most engineers aren't even aware enough to check that spec when selecting caps. It's easy to exceed the ripple current rating, then the caps overheat inside, drying out the electrolyte. This design even paralleled 2 caps, and it still wasn't enough! I learned about this back in the mid 90's, and have spent quite a bit of my career fixing power supplies with this issue. The spikes you're seeing are the inductance in the test leads you're using. At a 100Khz square wave, there's no way to get rid of them, and even a new capacitor will fail to filter them out. Some designs parallel smaller value capacitors with the larger ones, but this isn't necessary in this application. Excellent video, and I like your method of testing in-circuit.

So liking your explanations. Really want to get an oscilloscope now. Thanks.

thanks a lot .

Greate Video Thanks you very much

Anyone remember the Chinese capacitor fiasco of the early 2000s? It was mostly flat screen tv power supplies with them. I think it was mostly electrolyte drying out and / or low heat tolerance.

Great. Can repair electronics, greetings to all, I'm from a content creator from Indonesia

Holy. Buck rogers bat man , thats a cool desolder tool

Hi john. I would like you to do some video clips on how to repair an adapter charger (12, 24, ..) volts and also advise the common faults/damages on the adapter chargers. There are a variety of adapter chargers such remote control toys, scooters, etc.. batteries chargers. Just simply pick any of them as examples. Thanks

Very interesting and informative as always !! My pool pump was having more and more difficulty starting last summer and as you said, it finally would not start at all...Main suspect was the big capacitor ...Changed it, and bingo....Starts like new. But now with your video, I will be more confident to try it with household electronics ! Thank you M.Salt .

Built an ESR meter when I was a young tech in training. They are worth having and provide a reliable indication of a bad capacitor in circuit too. But your method of the function generator and CRO works well. Guess they aren't CRO's anymore having digital screens. Fun fact, the first digital oscilloscope I ever used was worth $80000, how times have changed.

Thank you so much...can you please show how to select the correct filter cap for a transformer less supply?

Nice informative video. Learned this simple trick. 👍 Please some time make a video of how to identify a bad SMD capacitor in a mother board. Thise are pretty small and no markings on it.

It's actually pretty shocking how many semi-"new" stuff stops working because of failing caps. I had several DVD players on my healing bench not older than 10 years that stopped working because of failed caps while most of my 30-40 years old hifi equipment runs still on it's original caps.

Yep, JCCON do go bad, have replaced them on motherboards. It seems the ones that go bad are the ones that are the smallest size for a given spec. If using sketchy caps, I'd go up in voltage if room permits.

nice! Many ppl dont know our appliances like LCD LED TV mostly wont boot up also cause by bloated capacitors....😊

Hi I recommend two toys: BSIDE ESR02 Pro and/or MESR 100

hi gold caps are much better than the other ones

Lady in a parking lot said her car would not start needed battery boost. She had her friend change battery and it did not help and several shops told her itcwould need expensive diagnostics. I was late for a job,but I said I take a look. Opened the trunk took a 7/16 wrench tightened up terminals,then with no boost I said try it. Little sliw but it kicked over and ran. Left her my biz card ,asked her to let me know if it failed again. She called me up on a friday and then E transferred me a couple of dollars.

Replaced 160v 47uf caps on my tv p/s board with 300v 1000uf. The TV turns on and works fine, do you think I'll have a problem later on?

Hey interesting stuff 👍 Do you have anything on how to check spike absorbers with multi meter. I am wanting to check a couple of Fettec spike absorbers

I WAS AT A RECYCLE DAY, GOT A JUMP PACK WITH INVERTER, JUST CHANGED OUT THE BATTERY, AND A DVD PLAYER WITH A BAD POWER SUPPLY. THREW AWAY THE P S AND I NOW RUN IT ON EXTERNAL 12 VOLTS FOR THE AUDIO CIRCUITS AND A STANDARD 5 VOLT REGULATOR LM7805 WELL HEAT SINKED TO THE FRAME, PLUGS INTO ANY 12 VOLT POWER OUTLET MAKING IT PORTABLE !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Thanks a lot! You taught me the positive and negative terminals so I fixed it! But do you really need soldering wires?

Excellent and very useful! Do you ever discharge capacitors before replacing them?

Never saw this oscilloscope setup before, do can you make a video explaining what is a function generator and how you plug it in and use it aside from caps testing?

Does this method works on in circuit capacitors or uou always need yo detach them first?

My general approach to testing electrolytics with a multimeter or capacitance meter is: if capacitance is way out (over 50%) the cap is definitely bad. If the capacitance is in the right ballpark that still doesn't mean the ESR is good, so slightly inconclusive. Apparently high ESR will throw capacitance readings off, at least sometimes, so a much higher capacitance reading than the cap value does tell you the ESR is too high. Annoyingly you can't trust in-circuit measurements and not all bad caps bulge or leak visibly. In fact, out of all the rotten apples I've replaced, only a handfull showed visible damage. All the others looked fine. You can get very affordable component testers that measure ESR, among many other things. These testers can check many different diodes, transistors and other electronic parts and seem to be fairly reliable, especially for their price. The most common model is the LCR-T4.

I had to replace the 2 power shottky diodes in my brother in laws sony radio cd player as they were both loosing power by half its proper full value total. There was no power at all to the board. I did check all the capacitors and they were working fine.

John; I' m fixing a Jennings slot machine. Could I replace a 1.0k Tantalum Capacitor with a new 2.2 Electroletic capacitor. Same voltage.

Thanks for posting this! Is there any way to check a capacitor while it's still in the circuit board?

Hey unrelated to the vid but I have a cassette deck that requires tuning with a 1khz at -10db signal , what equipment do I need to do that?

Thank you for the Video. Do I need to worry about the Ripple Current rating of the new capacitor? Some people are very serious about them and some don't even bother thinking about them.

Thank you, John, for your video,awesome equipment. what brand of capacitors that you are using for repair?

I have a radio HITHACHI 32 years old stereo, its one side sound very low should I replace all capacitors, I think so, please give me some advice

Wait, i was thinking that you can place both more Voltage and more capacity in microfarads? Like you can safely put 25v 3300uf instead of old 16v 2200uf. Am i wrong?

Hi My 25 yr old car radio stopped powering up. I changed the two 2200uF capacitors in the power supply and it didn’t help. Could it be the other capacitors on the power supply board? Thanks!

I picked up from other electronics. Videos that if you spot a baby blue capacitor, it's a Sanyo. And it's absolute garbage: -ergo- replace. Do you concur?? I eagerly look forward to your response

could you use caps from an old PC motherboard per say that still aren't bulging and leaking?

Can you tell me what is wrong with this TCL Model: 43S421 TV I thought it was just bad contacts on the ribbons, but I cleaned them, and it still flickers. I took a short video clip of it, but I don't know how to send it in this

John in your opinion, what variation in capacitance value would be deemed acceptable / safe when replacing caps .. eg the value of a cap to be replaced is 47uF at 25v, the new replacement cap both being 25v when tested read as being 45uF and 49uF with low ESR, would a person use them or not? .. Thank you.

Thank you for sharing the knowledge! Slightly off topic question: Would you know of any advantages of getting Hantek DSO5102P or Rigol DS1202Z-E oscilloscope? Both are 2-ch. in very similar price range. Hantek is 100MHz which can be hacked to 200. The Rigol is 200MHz factory. Thank you in advance!

In this case it is clearly seen that the capacitors are perforated. I really liked the desoldering gun, I had not seen it before. Could you tell me if it is possible to buy it somewhere? Thank you.

can you help me with what is CP802 on a samsung TV Un46fh6030f power supply board??

can use audio signals to test caps? say put a cap in series with the output of an mp3 player to the sound input on your computer? if the cap is bad it will let a different frequency through or even crackle.

The MESR-100 V2 is awesome. You can also test the resistance or microhenries of the inductors with the esr meter. The reactance formula is 2𝛑FL. That would be 2 x 3.14 x frequency of esr meter which is 100 kHz x 100 (uH) Just plug it in to get the reading. R=0.628 X L(uH) L(uH)=R(ohms)/0.628

Wouldn't it be good to clean under the capacitors that leaked before replacement?

My 2 NAD stereo receiver power supply filter caps are rated 4700uF 50V. Are you saying I shouldn't go over 4700uF but volts are okay to bump up?

What's the name of the handtool you use to desolder?

Do you have to observe the polarity when connecting them to a multimeter? Which is the positive in that case?

Hey John I’m looking at buying a ksger t12 station and wondering if it’s still a good station. I also can’t decide between handles

4:42 most likely they have a lower ripple current rating which is important for caps used in power supplies. caps with lower ripple current rating will heat up faster and run much hotter and have a much shorter life.

I wish I had a blue ray player. and a blue ray disc.

Where do you buy capacitors if you're fixings these electronic parts?

John that method works for capacitors of a wide range of capacitances or do you have to adjust frequenvy and/or vpp ?

Is there a preferred brand of capacitors to buy?

Hi, is there a link to purchase the soldering kit you used or one that you would suggest getting for this type of work?

Is it common for the electrolytic fluid to be that dark color? Or does it change color over time?

Some oscilloscopes have a signal generator to calibrate the probes and working at 1 KHz/5V : can we use that signal instead if we don't have a signal generator available ?

Thanks for the video, but you didn't say or explain why you didn't check or change out any other caps on the power board...?

our Blu-ray player has been acting up in us for some time now, I didn't realize capacitors could be the cause though..! 🤔

Esquire Which tool you are using for remove capacitor please name

What is ESR?

i have a blu-ray player that crapped out on me, it looks alot like the one you;re fixing

Where did you order from, were they local? I used eBay but didn't see the shipper till a tracking # was produced. (China) It may be next year before I get them??? Where a distributor for a future purchase 🤔!

If a capacitor is smaller than what you want to replace, it may only mean that is made with newer techniques.

Do you look for what caused the fail?

Today i learn. My tv have got two capacitor get bloated like that

🤗👍

You put in those new caps right away, aren't you supposed to tin the leads first, to avoid cold solder joints ?

Blacklisted devices wreck their capacitors, typically seen on old P2 motherboards. Seems that a legalized, activated device fixes the capacitors by charging them correctly. So if a laptop had previously an illegal Win, by replacing it with a legal one, correctly fixes all components without the need of replacing any parts.

Nobody wants to desolder every cap to test, what's best way to test in circuit on pcb ? ESR test ?

Loads of gunk has come out of the one I wanna replace and over a bit of the board! Can I replace the capacitor and leave the gunk there ? Lol

Electrolytic should be same size or bigger. ISR - switching g loses in PS

I purchased a box of Chinese ChongX capacitors. Later I discovered they are not good quality. Should I throw them away?

But this method does not work for low ESR capacitors? You are using AC voltage on a high ESR value capacitors here.

Time bomb caps, made just to last the warranty

*with