Introduction: Repair Your Electronics by Replacing Blown Capacitors

Picture of Repair Your Electronics by Replacing Blown Capacitors

Checking for blown capacitors in your malfunctioning electronics is fast and easy if know what you're looking for.  Replacing one part at a couple dollars a piece is much cheaper than replacing an entire monitor for hundreds of dollars!  Monitors, digital converters, and other video- related electronics commonly have power issues that are caused by faulty (read: low quality production) capacitors.  Common symptoms include:

- Unit won't turn on
- Unit won't return from standby
- Unit turns on and off intermittently
- Screen flickering or distorted
- Lines across the screen

If you're experiencing any of these, it's worth taking several minutes to check your circuit board capacitors. 

Step 1: Tools Needed

Picture of Tools Needed

Checking the capacitor just requires your eyeballs but replacing them requires a few tools:

- Screwdriver, hex wrench, or whatever's needed to open the case
- Soldering iron
- Replacement capacitors (you will find the values for this in the following steps)

Also optional but helpful is soldering wick, which is available for fairly cheap at Radio Shack.

In this example I'm repairing a digital TV converter box that will power on, but does not activate from standby.

Step 2: Open the Case

Picture of Open the Case

Most important: power off and unplug your unit!

Using your screwdriver or other tools, open up the electronics case so that you have easy access to the circuit board.  If you're having trouble, look up the manual online to find out where the various screws and tabs are to open the case.

Bring it up the light so you can see the electrolytic capacitors easily.

Step 3: What a Blown Capacitor Looks Like

Picture of What a Blown Capacitor Looks Like

A busted capacitor can be obviously broken (leaking brownish fluid, corroded, or with the leads severed), but sometimes it's subtle. The top of a blown capacitor will be slightly bent outwards in a convex shape, rather than flat or slightly indented inwards like a working capacitor.  See the photos above for examples. 

Think of it like a vacuum-sealed glass bottle.  When the seal is intact, the bottle cap is flat, and when you break the seal, the bottle cap pops up.  That subtle "popping-up" is exactly what you're looking for.

Step 4: Remove the Old Capacitor

Picture of Remove the Old Capacitor

Make a note of the polarity of the old capacitor, and mark the exact values you'll need for the replacement: capacitance and voltage/temperature ratings (these may be written on the part itself, or you can look up the part number).

Press the tip of a heated soldering iron directly onto the solder joint on the back of the circuit board that is holding the old capacitor down.  Hold on to the capacitor itself with your other hand.  As the joint melts, you can feel the tip of the iron fall into the hole of the circuit board.  As soon as it does, pull that side's wire lead out of the board.  Then repeat with the other side.

This can take a bit of trial and error.  The goal is to dig the very tip of the iron into the joint so that the solder in the hole heats and melts.  If there's too much solder for your iron to reach the hole itself, you may want to use a soldering wick to get rid of some of the excess.

Also, be aware that some manufacturers use solder that cannot be melted by a typical hobbyist soldering iron.

Step 5: Insert the New Capacitor

Picture of Insert the New Capacitor

Trim the leads of the new capacitor so that they are both even, and will sit at about the same height as the old capacitor.

Position the new capacitor leads at the holes where the old capacitor was, with the correct polarity.  Just like before, press the tip of the soldering iron directly onto the joint in the back of the circuit board.   As soon as the tip falls into the hole, press the wire lead through the hole, then remove the iron.  The old solder joint will solidify around the new part and hold it secure.  Repeat with the other side.  Add new solder to the joint if necessary.

Step 6: Working Now!

Picture of Working Now!

Replace the circuit board in its case and test the power and output.  The electronics should work now!


Osk33 (author)2018-01-03

I wanted to replaced two capacitors on my Samsung circuit board. In the process I accidentally removed the copperhead pads. Can I still solder the new capacitors and how would I do it? Thanks in advance

RaviT120 (author)2017-11-23

250v185j cl21 capacitor burned from old portable rechargeable fan what can i do.. pls help me for replacement capacitor in india

Jason B (author)2017-10-01

Hey guys. I have a craftsman/liftmaster garage door opener model 41A5021-1l. Had a lightening storm, tripped a breaker, and now it's dead it seems. Completely. Even the GFI outlet it was plugged into needed replaced. Pulled the board out and noticed maybe two smokey areas on the board. I can buy a new board for $75 but I don't think this issue is a bad sodder joint. Here are some pics. Any ideas? And on the blue capacitor (not really near the smokey area on the board, the teeth are super pushed out? Ideas?, Kinda a newbie. (i can also add more photo's if need be)

JoelG110 (author)2017-06-12

I have a 65" Panasonic Plasma TV model TC-P65S2

Last night I heard a bang like an M80, and the TV turned off. I unplugged it from the wall, and while doing so, smelled burning stuff.

I took the case off today and checked all the capacitors, and they looked great, except the two 230v1000 in the picture, (closest foregound, and behind at medium distance) they both had slight bulges. Is it likely they both blew at the same time and produced one bang noise?

JoelG110 (author)JoelG1102017-06-12

Also, I have a 7-blink error code, which indicates a problem with the Driver SOS 2 SU / SD / SS Boards (SC floating voltage area)

JoelG110 (author)JoelG1102017-06-12

I just disconnected the Y-sustain board(s) and plugged the TV back in and it went from 7 blinks to 6, which as indicated on a youtube video I found, that the Y-sustain board is the problem, but I'd like to narrow it down further as the Y-sustain consists of three boards, the 5175, 5184 and 5185, each of which costs about $100 and is out of stock every where

JoelG110 (author)JoelG1102017-06-12

I have confused further by finding a diagram showing the 5184 and 5185 boards form a buffer board...

victori33 (author)2017-01-25

i have a samsung plasma tv model; ps42b430p2w that was making a clicking sound and not powering on. all capacitors are good not physical damage. so i change the bad that i assume was bad . after replacing the board LJ41-06613A. the \Tv is turning on now no clicking sound, but it stays blank no pictures. what can i do

russvan (author)victori332017-02-10

sounds like you need to replace the controller board as well? Maybe you had a voltage surge or something and it knocked out both boards?

HelloKitty3636 (author)2016-09-21

Question... Please help! I pulled my capacitors out before reading how to remove them (I know... Stupid) and have all the tools and new capacitors now. How can I fix my problem? I can still see part of the old wires in the hole. Should I take a sweezer and heat up the back and follow through with the removal instructions or just solder new ones onto the old wires? Thank you to anyone who can help me with my dilemma!

I meant "tweezer"

archp2016 (author)HelloKitty36362016-12-05

Did you get it sorted out in the end? I haven't done mine yet. My son who is an electrical engineer but lives on the opposite extreme of the continent warns me that replacing capacitors is much more difficult than what most tutorials like this one would have you think. I'm 71. I doubt if I have the quality of eye sight and steady hands he feels are needed for this work. He wants me to let him buy me a new tv for Christmas.

HelloKitty3636 (author)archp20162016-12-06

I did and it works great. Only issue now is it turns on by itself in the middle of the night. Ha! No idea why

archp2016 (author)HelloKitty36362016-12-05

Did you get this fixed up eventually?

longson90 (author)2015-11-15

i have a samsung 32 inch smart led tv it turns on with image on the screen with sound but no back lights are working could this be a power board problem

mtbike2 (author)longson902016-10-17

backlight bulb is probably burned out. I don't know anything beyond that

HelloKitty3636 made it! (author)2016-09-21

It totally worked!!! Thank you so so much for this diy!!!

HelloKitty3636 (author)2016-09-21

I did it! Yay! Works like a charm now

Morris SB (author)2016-08-28

I have a sterio in my living room but current went into it and now it has stop coming on. Someone please help me.

johnbe888 (author)2016-03-24

On the body computer in my car it looks like a capacitor has failed . This is of the design known as "Case E" I cannot see any simple way to remove the faulty capacitor - and therefore also any way to easily re-solder the replacement - how is this type of capacitor attached?

Vickyx1989x (author)2016-02-19

Hi I have a Sony tv stuck in standby mode where do I buy capacitors? I'm highly struggling with this any helps appreciated hugely

GregoryB41 (author)Vickyx1989x2016-02-26

milkywayman (author)2015-07-25

Sometimes a bad capacitor has no external signs, this actually happens when they dry up. I had a failed PSU once, and I measured the caps using a cheap ESR meter (check on ebay). The failing cap had still the nominal capacitance but the series resistance was off - instead of being below 1 ohm it was a couple of hundreds! And the rest were also in bad shape, if they weren't failing yet, they would have soon.So if you're in the process of replacing one bad cap, do yourself a favour and simply replace them all :)

habze (author)milkywayman2015-10-18

I have a Samsung Ps50a457 model, i replaced 2 bulging caps, the tv then worked for 2 days and failed on me again, I am assuming the other caps are faulty aswell BUT which caps am i suppose to change on the power board? There are around 12 caps in total. It is doing my head in please advise.

milkywayman (author)habze2015-10-19

Change the small voltage ones, not the 450V - those are usually ok. Also check this thread: It can also be a symptom of cold joints that is giving you problems :)

habze (author)milkywayman2015-10-20

So do you know the difference between CM402 & CB402? Should i just change the caps which are mounted on the CM places? Very confused as all the caps are looking fine, also why are there different coloured caps? Do they mean anything :-)

iolamis (author)2015-01-27

I am trying to repair an Arri 1.2KW HMI magnetic ballast from 1995 which flickers irregularly. I found this capacitor which looks blown in that the top is convex, but I measured it with my fluke 179 meter and it came up 230uF. It doesn't seem shorted as I get very high resistance measurements (settling around 11KOhms after starting much higher as I assume the meter battery charges it slightly confounding the resistance measurement). Since this has a black plastic top without any grooves, unlike the metal tops with grooves that I typically see, I'm unclear about whether this means it is blown.

milkywayman (author)iolamis2015-10-19

It does look bloated, I suggest you replace it. Sometimes bad capacitors will show correct capacitance but their internal resistance has increased - and this is not measured by most universal meters :)

BainM (author)2015-05-16

thank you you for all this great info... I have a JL Audio 500/1 car subwoofer amp. it powers on and has no sound i looked everywhere and tested everything and it all checks out. i see the tops of the capacitors are bulging and they are 1200uf 100WV and i Replaced them with 2200uf 80V would this not be a good idea? i have not powered it on yet. i dont have any matching but these are the same type of caps with plastic tops instead of aluminum i pulled them from a hifonics 1200 watt amp. i just dont want to damage the board by powering it up and it not be a match.

milkywayman (author)BainM2015-10-19

While increasing the capacitance is not a bad thing, the important thing is that you at least match the voltage of the capacitor and the temperature range (80 or 105 deg).

BainM (author)2015-05-16

also the capacitors i pulled off. i tested them with a 9 volt and my multimeter... is that not a good enough test because they seemed to work or do bad caps still hold a charge? lol. thank you and anyone feel free to jump in on this if you know

milkywayman (author)BainM2015-10-19

That's a bad test, they will hold charge unless completely dry.

ooofest (author)2014-10-03

This was successfully applied in fixing a subwoofer for an Advent AV190 computer speaker system - even down to the "blown" capacitor picture resembling my issue. Very helpful, thanks

jmichaels4 (author)2014-02-19

Is it possible to have a blown capacitor WITHOUT any visible change in it? That is, no distortion of the top, etc.?

ahero4heor (author)jmichaels42014-02-23

Yes! Use an ESR meter and/or capacitance tester to check (they are not the same as a multimiter though some of the very expensive ones will come with the functionality) the capacitors. They run about $80 for a decent ESR meter. If your electronics aren't worth that much I would simply replace them, though.

iq201 (author)2014-01-12

Discharge all capacitors in the vicinity. It's best not to assume they're all discharged.

jgeidl (author)2014-01-09

Nice job. I love hints.

raptor402 (author)2013-03-18

Hello, sir/ma'am

Your instructable is wonderful. I have a question: I have an XBox 360 slim with a 100-127v input power supply. In my country, the wall outlets are all 220v, so I was using a step-down transformer with the console. Unfortunately, I tried out a smaller converter without reading that it was not transformer based. To sum it up, there was a bang and some smoke.
I opened up the adapter and found that one big capacitor had burst open (that was my first guess as I had seen a capacitor burst with my own eyes, and that was my own doing) and the electrolyte was spread around. I cleaned up the electrolyte and tried the adapter. The console would work for a minute and then shut down, implying that the rest of the adapter is function.
My question is: will replacing the capacitor fix the adapter and make it usable again?

rbennett8 (author)2012-09-03

i can vouch for this i had o recently recap my 26" lcd tv due to it turning on and off intermittently

i recommended this site they will help you out a lot with the process

also the desoldering wick from radio shack from my experience is junk

this one is good i have not had a problem with it yet

crowman73 (author)2012-05-15

I'll definitely use this tip in future, thanks.

nickmccullough (author)2012-05-13

thank you sir, very helpful.

i had a DVD player stop working, turns out it blew the switching power supply IC, and a fuse as well. I replaced them and the unit still didnt power on.

i had overlooked a couple of blown caps, so thanks for reminding me to take a second look! all is functioning well

Dr.Bill (author)2012-05-13

I always suspected the tops of the caps were scored for a reason.

Horsehockey (author)2012-05-12

You say to note the polarity of the capicator. Trying to determine the polarity of capicators, especially on well pump motors or other outside erquipment, has always baffled me. Maybe the little blue capicators have the polarity on them.
I have asked many highly intelligent electronics technitians how to determine if a capacitor was bad. Their reply was that if they thought it could be bad they replaced it. You are the first person I have seen that has come up with a simple way to dewtermine a bad capicator. Thanks for sharing.

fhidiort (author)Horsehockey2012-05-12

Usually electrolytic capacitors have a stripe with minus signs down the side that indicate the negative lead. You can see in the Step 5 picture the blue capacitor has a black stripe with blue minus signs- that's the negative end. Also on some circuit boards (including the one used in this example) the polarity is marked on the board itself with a little plus and minus sign.

dimmaz88 (author)2012-05-06

Awesome instructable. The trick for identifying the broken capacitors is great, I've always wondered how to do so.

Thanks for sharing.

samalert (author)dimmaz882012-05-08

coming from non electronics i was really glad you explained the thing with simplicity. Loved it !

fhidiort (author)dimmaz882012-05-07

Glad it helped!

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