Blown capacitor replacement

[Skyhooker]

Have any of you guys ever replaced leaking capacitors on a mobo? I was given an otherwise OK HP desktop that I was hoping to use as a test bed, and after repeated lockups while trying to reinstall Windows, I took a look at the board itself - at least half a dozen caps are blown. I'm guessing they're from that company that had the bad electrolyte formula a few years ago. I could pick up a replacement board for about $30-40, but this might be a good excuse to learn soldering. Think it's worth the trouble?

Thanks!


Sky

 

[jj2000]

hey if you are willing to give it a go do so,but remember that you could completely bugger up the mobo so if you dont mind losing the board it is a good way to learn and if you do it right you have just saved yourself 30 or 40 bucks in the process.

 

[14049752]

I've replaced several parts on various motherboards, replacing the capacitors on desktop boards is very easy. If a replacement board is only $30-40, I'd chalk it up as a chance to learn without having much to risk if it doesn't work.

Just make sure you match up the caps correctly, don't reverse polarity on them, and you'll probably do fine.

 

[Pc Fixed Right]

I have been wanting to try stuff out like this. What soldiering iron do you use or should use? or will any do?

 

[14049752]

What soldiering iron do you use or should use? or will any do?

I'd recommend a digital, adjustable soldering iron. No specific brand comes to mind.
If you plan to do a lot of soldering, I really highly recommend getting a hot-air rework station. It's the same basic idea, but with the rework station desoldering and soldering to boards is a lot easier..... I've replaced network jacks, power jacks, usb ports, audio jacks, and just yesterday replaced a vga port on a Dell laptop. There's no way I could have done that with a soldering iron.

 

[iptech]

a replacement board is only $30-40

That's why I wouldn't bother even attempting a repair, it's not commercially viable and a new board will be of a far more modern spec that one that's old enough to suffer blown capacitors.

 

[Skyhooker]

Thanks for the replies, all.

The board is a bad paperweight in it's present condition, so no way to screw it up worse (unless I electrocute myself or burn the place down, that is). I want to learn soldering so I can do repairs, especially laptop repairs, like those mentioned above. If it's not too tough a repair, it might be a good one to cut my teeth on. I've been looking into hot air rework stations since someone mentioned them in a post here last week, so the timing is good, too. It would make no sense just for the sake of the board, but would certainly add to my range of services.

Anyone know a good place in the US to buy capacitors and other such components?

 

[14049752]

That's why I wouldn't bother even attempting a repair, it's not commercially viable

Sometimes it's more commercially viable to learn a skill than it is to just replace.
Tell my customers that paid for a $20 video jack instead of a $200 motherboard that it's not commercially viable for me to know how to solder. The idea is that the board is cheap and capacitors are literally only a couple of dollars, so it's a GREAT part to learn to solder on.

Anyone know a good place in the US to buy capacitors and other such components?

For capacitors, you can probably get most of them at Radio Shack, believe it or not. If they don't have them, Mouser Electronics will, you just have to know a lot more about what you're buying.

 

[Czarman]

Skyhooker,

I had saved this article about replacing capacitors on the motherboard. I hope it helps.

http://www.tomshardware.com/reviews/fixing-motherboard,1606.html

Good Luck,
Czarman

 

[TechGuy71]

Badcaps.net sells high-quality (Rubycon) capacitor kits for quite a few motherboards that are known to have bad capacitors from the factory. That way you don't have to buy each different capacitor needed in a minimum quantity. I recently purchased a kit from them to repair the mobo on a Dell GX270, and it went great... saved the customer around $150 and actually made more doing it this way cause it was mostly labor.

My recommendation to you is to invest in a bulb-type desoldering iron. Radio Shack sells one that works very well for $10.99. This will save you a LOT of time and frustration in getting the old caps out quickly and cleanly. The soldering iron you use to solder the new ones in is a matter of preference. I use a digital adjustable iron, also from radio shack, but at $70 it is a bit pricey if you wont use it often.

Good luck! Let us know how it goes...

ps... whatever you do, do not use one of the "cold heat" soldering irons. They actually work by closing an electrical circuit using whatever you touch it to. and of course you don't want to send that current though your board...

 

[Skyhooker]

Thanks again for the recommendations and well-wishes, guys! I probably won't do the job for a few weeks, though; with all the expenses of getting this biz started, moving to a new place, etc, money is rather insanely tight at the moment, so I'll be spending the money on business cards, flyers, and so forth for a while. Also, I plan on picking up a hot air rework station like this one as soon as I have the spare cash:

Aoyue 968


which looks like a piece of equipment I won't have to replace, and will work with me, not against me (especially being a noob at electronic component repair). It's not cheap, but I'm sure it will pay for itself after a few jobs. Whaddya think?

Thanks again!


Sky

 

[pauln375]

Good learning project however

this would be a good test project however do your research first and make sure
that your board and caps are the ones that started bad or you could be wasting your time and money on the new caps because if the caps were not the ones bad from the factory then the new ones will just go bad also because of the underlying problem that you treated the symtem of or maby ime just to frugal with my money and time just adding my thought hope it provoves thought

 

[PcTestCard.com]

You can look for the same model capacitors from the similar non working mainboard. 2 non working mainboards make a working one.

 

[Skyhooker]

My adventure so far...

I received my new hot air rework station in the mail yesterday, set it up this morning, and got to work. I removed the first couple of caps using the soldering iron, which took quite a while and was a tedious job (I probably have the wrong shape tip). Next I set to work with the hot air gun. It took a while to find the right mix of temperature, airflow, and technique, but the last several caps were removed cleanly within a few minutes. Now I'm waiting to hear from the fellow at badcaps.net regarding a replacement set. I can't wait to try my hand at re-soldering!

I can really see how this will be a useful and profitable skill, and now I won't have to turn away things like laptop power jack repairs.

FYI: the bad caps on this board were Nichicon HM(M) series - might be worth checking any old boards you have or use for these to avoid trouble.

I'll report back again once I receive and install the new ones.

 

[mnoakes]

Spare Parts

I collect all old motherboards and other spare parts I can get from Customers for nothing.

All completely blown motherboards, I strip all usable parts from the board capacitors, batteries, jumpers and anything else which I might think would be useful later down the track.

All capacitors I check with a capacitance meter (which are very cheap to buy), then sort them in there different capacities and physical sizes.

Another tip with the PC recycling, is that I completely strip all Computer cases of nuts, bolts, screws, back planes, rubber feet, gromets everything that might be useful later.

With the left over metal cases, I sell to a scrap metal dealer.

Even dead Hard Drives are kept, because I have recovered alot of people's data with replacing circuit boards on hard disk drives.

I usually teach my staff to use a soldering iron, by stripping all the useful parts of the motherboards. This is a great teacher in the skill of using a solder iron.

From my past experience, when replacing swollen capacitors, I use the exact same voltage and farads size capacitors. But you will see certain motherboards with the same swollen capacitors, so I usually replace them with a capacitor with the same farads but with a higher voltage one. I find this stops them coming back in with swollen caps in a few months.

Personally the fake capacitors story is partly to blame, but I think NOT enough RD and testing is done when they are designing and manufacturing these boards. Or the manufacturers are putting capacitors on with just enough lifespan to cover them past the warranty period of 12-18 Months.

Cheers
Michael

 

[RoboGeek]

Better late than never...

Just found this thread. I'm posting on it from a linux box running on a HP that had 7 bad caps, and its going through a Netgear GS108 that had 4 bad caps. My data recovery machine is a lightning strike victim I had to replace a few things on (blown caps and regulators), but its been running over 3 years now. I currently have 5 PC's for sale that are all failed capacitors on compaq and emachines.

Parts are dirt cheap - I think I paid $.04 a cap at digikey because I usually buy 100 at a time

This also goes along the lines of replacing bad power jacks in laptops and other fun things

 

[pauln375]

Better late than never...

Just found this thread. I'm posting on it from a linux box running on a HP that had 7 bad caps, and its going through a Netgear GS108 that had 4 bad caps. My data recovery machine is a lightning strike victim I had to replace a few things on (blown caps and regulators), but its been running over 3 years now. I currently have 5 PC's for sale that are all failed capacitors on compaq and emachines.

Parts are dirt cheap - I think I paid $.04 a cap at digikey because I usually buy 100 at a time

This also goes along the lines of replacing bad power jacks in laptops and other fun things

I agreee my other post was just a warning Sorry it sounded so closed minded I have had some cap replacements come back to bite me a few months after thats why I say do the research first and would suggest that after a replacement run for a few months constant for testing also make sure on the ones that are the caps as trouble don't use the cheapest caps you can buy look at the tolerance rateing 2% are about the best I have found tho most sell 15% I believe that replaceing a cheap part with another one that will likely fail again is like putting a band aid on a severd limb
alot of emachines and compaqs had bad caps from the factory some went bad due the bad power supply the were shipped with but some were due to a bad surface mount IC chip with like 100 pins soldered on all four sides and also underneth those ones I dont have the tools to replace But enough info is out there for googleing to find out which ones were what starting error
Sorry for rambling and poor spelling .
Hope this clears up my earlier closed ended statement

 

[Rider]

As someone that's been soldering for 20+ years, here are a couple of tips. First, use flux. Clean your work before during and after. The biggest mistake I see people make when soldering is applying the solder to the iron and then to the component. If you do that you're not soldering the component, you're glueing it with solder (cold solder joint). To solder properly apply the iron to the component and then apply the solder to the component after it is hot enough. Which brings me to another tip, use heat sinks whereever possible, many components don't like the heat.

These are very basic tips and there are alot more that are very important as well such as preparing the surface and the iron, tinning, temperature, and so on but it's too much to get into here.

Good luck.

 

[Skyhooker]

Thanks for all the tips, guys! Not a single word of advice is wasted on me - I'm a humble noob at all this, and thus a sponge.

I've been scouring the net for soldering advice as well, and have also found some great Youtube vids on the subject. No sense in doing a shoddy job that's going to go bad (or not go well in the first place).

I just placed my order for replacement caps from badcaps.net. It took them a bit longer than the 24-36 hours they promised to give me a quote on a custom kit (4 days), but I'll let that slide

I plan to spend some time until I receive the kit in practicing on some junk components before operating on a live patient.

Thanks again!


Sky

 

[stevenamills]

All capacitors I check with a capacitance meter (which are very cheap to buy)

Cheers
Michael

Michael,

Any recommendations?

Thanks.......
Steve