Repairing a blown Capacitor on a router

mayhem

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Repairing a blown Capacitor



One of the most common thing’s to blow in modern day electronics is The rotten old capacitor so really to save a lot of money in these modern days is the ability to problem solve and fix this little buggers. From flat screen tft’s to graphics cards and so on, it really will save you a fortune in long run by replacing the parts yourself.

First off signs and symptoms that show a blown capacitor. Let’s take a good example here from below.

I was called out to fix a router that was only moving files at .2mbs across a network and any internet activity was less than having a 45kbs modem. After getting there I found the router and promptly placed my hand on it to feel hot it was. The heat was well over the top and the first words to come out of my mouth were “Yup a blown Cap”. Taking my trusty little multi screw driver from my pocket I opened the router up and hello my little friend there she blows a nice little raised cap sowing signe’s of over indulgence.

You can easily tell these in several ways if a cap has blown because the capacitor will have either have split or risen to a bulge. Normally caps should be flat and there cross that is the top should not show any signs of splitting.

Blow is the picture of the router and the blow cap.

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Now the first thing to do is find the details on the cap to replace e.g this one is clearly marked on the side 25v 1000UF @ 105c. So after a little hunting I managed to get 5 for £1.28 + 50p post and packing. Since routers are normally New £50 to £100 or second hand £25 to £50 this is a viable cheap option to repair.

Pic below of the details of the cap.

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Here is a pic of the pcb underneath.

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Now using the soldering iron were going to heat up the points and remove the old cap out.

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Here you can some very doggy pic’s of me disordering the leg at the time pulling on the cap at the same time taking a photo lol. (so if i can do that any one do this whole thing)

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Once you done side then move onto the other and gently remove the cap.

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Now that’s done here you can see the new cap .... Ops ... i messed up and order larger caps than i needed but i don’t care its still going in ... Just a little extra modding is required to the case but hay that’s life. Normally you should try and place the cap with the same one but since this is the same rating ect ect it will work perfectly.

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Here you can see it now soldered in. Because of its size i have had to do it lay it flat but I don’t care lol...

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So once finished a quick test. As you can see its seems to be fully working so time to fire it up on the network and see how it goes.

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Perfect all working running at full speed.

The time to put it back together.

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Because the user decided they couldn’t wait 3 days they went and bought a new router and don’t what this one so i’ve ended up with a router i don’t need asp since im on cable lol ....
 
Truly interesting, but replacing the capacitor of a router is surely much more easier than replacing the capacitor of a motherboard?

Considering the size and what-not. :p
 
Ill take a photo underneath its just as hard. (not for me though have my work station so i just heat up the whole area)

you'll see nay way once i get the new caps. This is being written just to show ppl how to do it as i think its very common and to many ppl think its hard and to be honest it inst and can save a fortune.
 
It was a both a semi-rhetorical question (if there is such a thing) and a sarcastic one.

Do continue with the thread it will be an interesting read like every other thread you make. :)
 
With motherboards, how do you unsolder the caps, I thought that because of the process borads underwent to solder them, they were virtually impossible to remove the caps (or anything else). Be interested to see how this turns out.
 
even though most PCBs are between 4 to 8 layers when the place most caps on then go from top to bottom unless there surface mount like many VGA card.

With VGA card's the easy way to do it is the use a heat gun and soldier paste and gently using circular motion heat up the area to be soldered and then quickly place the cap on.

This method though is a the cap goes through the PCB to the bottom and what we do is either heat up the legs underneath and pull the cap out or using solder brain remove the solder and then replace with a new cap.
 
Cool Thread

Hi Folks, sounds a good thread, cant say this is something I have ever done so will be interested in learning...specially if it saves me money lol :)
 
Got a XFX 7600GT out of the tech-skip the other day with 2 obvious blown caps. Gunk oozing from the top of them - even tho they're "solid" caps.

Getting "guy in the lab" to replace the caps in the morning. I'm sure it'll be ok.

Same guy fixed my SkyHD by replacing 5/6 bulged caps. (happens to have 50million caps in stock, plus a cpc/rs access).

Mostly power regulation these caps.
 
name='Rastalovich' said:
Got a XFX 7600GT out of the tech-skip the other day with 2 obvious blown caps. Gunk oozing from the top of them - even tho they're "solid" caps.

I've got a blown Enermax psu couldn't see anything wrong with it at first but can now :) Cheers for this thread Mayhem ;)

Pic below shows the cap on the left has a slight bulge and like Rasta's it had jizzed a bit out of the top too.

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Mendage later :D
 
can you get pic of both side of the cap so you can see what its rating it.

But glad its helping you. Bet jim could real that cap off with out looking lol.
 
name='mayhem' said:
can you get pic of both side of the cap so you can see what its rating it.

But glad its helping you. Bet jim could real that cap off with out looking lol.

Hate to disappoint but that's a new one on me too. Normally Enermax units use jP (CE-TUR series) caps on the secondary side, but that one doesn't have the normal markings from what I can see in the pic. It's most likely something low voltage like 16v and around 2200uf but thats just a guess.
 
Got to add this is a common problem with these routers and not many people show hot to fix it.

what a bummer.

Any way i've just pointed them to this post.
 
Good job mayhem :D

One thing I've found handy when soldering in new components (especially when they have long legs) is to wrap some wire around the legs before you begin soldering. This helps dissipate the heat from the soldering iron and prevent damage to your new capacitors/components.
 
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