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View Full Version : Replacing buldged capacitors on a motherboard?


badfish2
11-25-2010, 6:38 PM
I have a HP desktop that randomly freezes / shuts down on a clean windows install. Thinking the mobo was going out I found 6 buldged capacitors that I'm considering replacing myself. The process looks pretty straightforward, heat the leads, remove, replace and resolder, make sure no leads were bridged.

Any tips for making this go smoothly?

NaughtyMonkey
11-25-2010, 11:06 PM
I've heard of people doing this, but never had the balls to actually try it. I'm sure there are guides online. Good luck and let me know how it works out!

five.five-six
11-25-2010, 11:10 PM
I have a HP desktop that randomly freezes / shuts down on a clean windows install. Thinking the mobo was going out I found 6 buldged capacitors that I'm considering replacing myself. The process looks pretty straightforward, heat the leads, remove, replace and resolder, make sure no leads were bridged.

Any tips for making this go smoothly?

there is a reason that the caps went out, if you don't fix that, then they will break again, depending on your prosesor/memory, you can probably find a NEW mobo at freys for $50 or a used one on ebay for $25

ke6guj
11-25-2010, 11:18 PM
there is a reason that the caps went out, if you don't fix that, then they will break again, depending on your prosesor/memory, you can probably find a NEW mobo at freys for $50 or a used one on ebay for $25yup, http://en.wikipedia.org/wiki/Capacitor_plague

robcoe
11-25-2010, 11:50 PM
I have a HP desktop that randomly freezes / shuts down on a clean windows install. Thinking the mobo was going out I found 6 buldged capacitors that I'm considering replacing myself. The process looks pretty straightforward, heat the leads, remove, replace and resolder, make sure no leads were bridged.

Any tips for making this go smoothly?

Be carful in removeing the caps, motherboards now have several internal layers of traces, if your not careful you can damage the plateing on the through hole and have an open inner trace. Both mechanical stress(solder not completly melted, lead scrapeing the wall, ect) or from heat stress such as having the iron applied to long, can cause these problems.

Also you might want to check your power supply, buldged caps usualy are the result of to much voltage stress or the result of a polorized cap being installed backward(unlikely). If its to much voltage putting a new cap in will just cause it to blow again.

Overall, given the time that will be involved in getting the parts and getting them installed, unless you have a high end motherboard your probably better off buying a new one.

E Pluribus Unum
11-25-2010, 11:58 PM
There is a reason they use robots to make motherboards.... its much cheaper and faster.

Buy a used MB that fits your hardware.

tgriffin
11-26-2010, 12:36 AM
HP is crap. There's your problem.

CSDGuy
11-26-2010, 12:37 AM
I had the same issue as well, but with a non-HP motherboard. I ended up getting a new motherboard and processor. I shopped around a little bit and found one that was compatible with basically everything the old board had. I eventually decided to get a new video card... Both systems had on-board video to begin with, so I'm not counting the video card upgrade... I put in just a little over $100 on the whole thing. I'm really happy with the upgrade. The rest of the system was fairly decent to begin with, so the upgrade went pretty smoothly.

As pretty much everyone else says: upgrade. Don't waste your time soldering. Once you get that done, why not use that old board to play with soldering? You're not using it anymore, so... and if you goof, well, you're not using it anymore... ;)

Dhena81
11-26-2010, 12:43 AM
I've never heard of anyone doing this in a long time techs now just replace the whole motherboard do you have a DMM? Capacitors are usually the weak link in most electrical circuits. Some of them might not be bad but if there buldging they most likely are. Make sure you get the right Micro Farad and voltage ratings if your seriously going to do this.

Corbin Dallas
11-26-2010, 7:48 AM
I've never heard of anyone doing this in a long time techs now just replace the whole motherboard do you have a DMM? Capacitors are usually the weak link in most electrical circuits. Some of them might not be bad but if there buldging they most likely are. Make sure you get the right Micro Farad and voltage ratings if your seriously going to do this.

Same here.

Also check your PS and make sure it's sending out the right voltage/amperage. A bad PS will cook a motherboard in a matter of seconds.


IF (and that's a BIG IF) you are going to replace the bad caps, make absolutely certain you are using a electronic solder sucker (read: not a bulb or wick type) and let the cap fall out under its own weight. If you PULL the cap out, you may ruin the top layer of the board.

Also, when re-inserting the new caps, tripple check the anode / cathode positions on the board and match the cap designations.

Screw that up and you'll be buying a new motherboard for sure.

GL!

badfish2
11-26-2010, 10:19 AM
This isi an extra tower I have, so not a huge loss if something goes awry. I heard the HP restore wont install on a non-hp badged mobo, that was my only hold up from looking for a new one. Thanks for the suggestions :-)

Matt C
11-26-2010, 10:21 AM
Get a new MB.

gunn
11-26-2010, 10:45 AM
The easiest repair is just to replace the board.
On my home server, I replaced the board, CPU, and memory for well under $100 (fry's motherboard w/ integrated video + CPU special + cheap mem deal).... but all this computer does is share my printer and store my files for access by 1-2 users (my wife and I).

As stated above, this problem isn't limited to "HP junk" -- I've replaced several of my boards & power supplies for this exact reason so you aren't alone. The explanation for the problem is listed in the wikipedia article.

If you want to go down the solder route, its really not that hard. Two issues:
- find a cheap, cost effective replacement may be a slight challenge. If you are trying to do it on a budget, check places like digikey or jameco may have it but it might not be cost effective after shipping. You might want to look on older boards (if you or a friend isi a packrat) to see if you can scavange a suitably sized cap.
- make a note of the correct polarity when you solder the new component down. Caps only work one way. Corbin mentioned this above...

These are probably the tips you were looking for other than the blanket condemnation of "just replace it". As for software, well, you are connected to the internet and all that stuff is easy to find...

-g

Merc1138
11-26-2010, 10:13 PM
Unless you're already good at this sort of work, just replace the board. The reason why I said that, is because a bad soldering job means time spent troubleshooting, which is time wasted putting it all back together, seeing that it doesn't work, taking it apart, resoldering, putting it back together yadda yadda.

Additionally, if you've already got some bad caps, if it's a batch issue you'll eventually end up with another blown cap. Unless it's some really high end component, it's just not worth the effort.

Krusher
11-26-2010, 10:45 PM
I'd say give it a shot, Make sure you get + and - right, and no not a smart *** comment, that can make or break a repair :)..

solder wick would be a great removal aide, and with something like this, it may just smooth out that system.
Capacitors are just not made like they used to anymore and have become more of a failure point over the years..

Good luck, if anything try as a fun project.. and let us know how it goes. Would suggest a adjustable soldering station and lower temp flow solder..
I have a HP desktop that randomly freezes / shuts down on a clean windows install. Thinking the mobo was going out I found 6 buldged capacitors that I'm considering replacing myself. The process looks pretty straightforward, heat the leads, remove, replace and resolder, make sure no leads were bridged.

Any tips for making this go smoothly?

orangeusa
11-26-2010, 10:45 PM
I design boards/hardware for tough environments. Caps never fail like this unless they went cheap on cap mfg, or didn't spec caps right.

As mentioned above, yeah, it's a piece of cake to replace them, but I wouldn't trust any motherboard that failed like this. It will only happen again.
HP has underwhelmed me in the PC market. Their test equipment is awesome and priced as such, but not the PC garbage.

I had ONE case where a run of boards failed, but it was bad components. Turns out the parts were counterfeited - no kidding - somebody in China had relabelled one IC which was in a couple hundred boards.. Took a while to solve that problem.... :)

gunn
11-28-2010, 7:48 AM
I design boards/hardware for tough environments. Caps never fail like this unless they went cheap on cap mfg, or didn't spec caps right.

As mentioned above, yeah, it's a piece of cake to replace them, but I wouldn't trust any motherboard that failed like this. It will only happen again.
HP has underwhelmed me in the PC market. Their test equipment is awesome and priced as such, but not the PC garbage.

I had ONE case where a run of boards failed, but it was bad components. Turns out the parts were counterfeited - no kidding - somebody in China had relabelled one IC which was in a couple hundred boards.. Took a while to solve that problem.... :)

Yeah, they went cheap on their caps... like much of the industry.

Also, isn't their test equipment now made by Agilent, a seperate corporate company altogether? :)

winnre
11-28-2010, 12:18 PM
We had that happen on about 15 dell boxes. We hit Radio Shack for the caps and replaced them all ourselves. Easy as 7th grade electronics class and much cheaper.

Of course, they were out of warranty, and I think there is a class action suit because of it.

badfish2
11-28-2010, 4:00 PM
Well I pulled the board out to check the bottom, and all the leads are pretty isolated from other components so I have plenty of room to work. Funny thing is, all the caps that are bad are identical, 9 total. Im going to chance radio shack and see if they have what I need and go for it :-)

sfwdiy
11-28-2010, 5:36 PM
yup, http://en.wikipedia.org/wiki/Capacitor_plague

I'd be willing to bet this was the cause of the problem. There were a huge number of bad capacitors that were made in the last 8 years or so. Every manufacturer got hit pretty hard with these problems.

When I was working at Apple I'd replace motherboards all day long that had bad caps. I'd see four or five iMacs a week with this problem. The replacement boards we'd get for those machines all just had the caps replaced. If you know how to solder you can replace 'em.

I replaced a video card in my media center Mac that had blown caps on it about a year ago, too. That one wasn't worth re-soldering. I wanted to upgrade anyway. :D

--B

orangeusa
11-28-2010, 5:46 PM
Digikey.com is your friend. Radio Shack has ceased to be a source of common electronics. (just my 2 cents here).

JDay
11-28-2010, 8:29 PM
Digikey.com is your friend. Radio Shack has ceased to be a source of common electronics. (just my 2 cents here).

Radio Shack still has all the stuff that used to be in the stores, it's just that you usually have to order it from their catalog, and don't expect the sales guys to know they sell this stuff. Their retail stores don't carry much beyond cell phones and cellular accessories these days.

badfish2
11-28-2010, 10:56 PM
Yeah radio shack only had a few pcb type capacitors, i'll be checking out digikey.

badfish2
12-06-2010, 12:15 AM
found the capacitors I needed at badcaps.net, placed the order and they shipped the SAME day! I ended up ordering and replacing all the "tk" brand caps on the motherboard, a little time consuming but worth the effort since I had the thing apart already. After replacing a total of 12 capacitors and reassembling, the computer booted right up!

It looks like I fixed the problem, the computer would always crash when running the "windows experience index", but passes now :cool:

Total investment: $15 in parts / shipping (I already had a 40 watt iron and solder)

Matt C
12-06-2010, 12:17 AM
That's awesome actually.

sfwdiy
12-06-2010, 12:22 AM
Badass. Way to refurb your own board. :thumbsup:

--B

WTSGDYBBR
12-06-2010, 12:36 AM
Replacing caps are very easy. Make sure you get the same voltage of cap's you remove. Let say 7v , 3300UF If you put a cap that is less in voltage you better believe it will blow up. Now on your cap there is a Negative and positive side make sure you identify the negative side when you replace it. It would be best to buy a solder sucker/solder soldering pump they are like $5 bucks and they will save you a ton of headache. You just heat the area were the solder is and use the pump to remove the solder from that area. You can buy caps at www.digikey.com of you need help or have questions I'm a wiz at electronics.

Below is what the negative side looks like
http://www.google.com/imgres?imgurl=http://blogs.courant.com/colin_mcenroe_to_wit/capacitor.jpg&imgrefurl=http://www.overclock.net/nvidia/812179-capacitor-help.html&usg=__qe3KTyfYbx8KMWZ3pp5t54jOmQI=&h=564&w=1081&sz=147&hl=en&start=19&zoom=1&tbnid=yaoeg4Bbu7btxM:&tbnh=75&tbnw=143&prev=/images%3Fq%3Dnegative%2Bside%2Bof%2Ba%2Bcapacitor% 26um%3D1%26hl%3Den%26client%3Dfirefox-a%26sa%3DN%26rls%3Dorg.mozilla:en-US:official%26biw%3D1366%26bih%3D578%26tbs%3Disch: 10%2C367&um=1&itbs=1&ei=_aD8TPHyCoGssAPMjrD3DQ&iact=rc&dur=184&oei=36D8TI-oH46usAPa16j3DQ&esq=10&page=2&ndsp=21&ved=1t:429,r:2,s:19&tx=68&ty=8&biw=1366&bih=578

Here is a youtube clip out to use a de solder pump.
http://www.youtube.com/watch?v=Aw4lZGk90i4

G-forceJunkie
12-06-2010, 12:45 AM
Timley post. My Dell went TU last week, wont boot up, and the first thing I noticed with the case open was bulging and leaking caps. I've bought a new computer (it was time, I've been holding off) I think I'll give it the $15 cap fix and see if that works, that would be the easiest way to get my data off the drives.