replacing the bulging caps?

[member101]

Any advice/tips on where and what replacement caps to buy?

One board (MSI K7T PRO2-A) needs:
2- 2700uF 6.3V
9- 1000uF 6.3V

The other board (EPOX 8RDA+) needs:
4- 2200uF 10V
5- 1500uF 6.3V
9- 1000uF 6.3V

Thank you in advance,

Member101

 

[Bobnova]

digikey.com has all kinds of electronics stuff, i'm sure they have the proper sorts of caps.

 

[member101]

replacing the bulging caps

Thank you.
I have the digikey catalog, problem is there are so many different brands and types of caps that match up, I'm just not sure which ones to buy.

I just thought someone else might have gone through this already and would know which replacement caps to purchase.

Thanks,

Member101

 

[CGR]

Supernade is the re-capping expert. Hopefully he will chime in and give you the best advice.

In the meantime, you can read his re-capping article. Not the same board, but probably has some similarities.

http://overclockers.com/index.php?option=com_content&view=article&id=3652&catid=54:howto&Itemid=4260

 

[member101]

Just wanted help with where and what new replacement caps to get.


Thank you for all the help.

 

[GrimX9]

If you are still here, i go to jameco for my electronic parts. They are cheap there and the website is more friendly.

 

[larrymoencurly]

In no particular order:

www.DigiKey.com
www.Mouser.com
www.BDent.com
http://stores.ebay.com/PC-MotherBoard-Capacitors-Store
www.TheCapKing.com
www.BadCaps.net
www.CapsMod.net

Motherboards and switching power supplies need low-ESR capacitors that places like MCM Electronics and Jameco normally don't stock.

 

[vgta88]

if you don't mind me asking, btw the link doesn't work for me. How does recapping work?

does it revive old electronics already blown or leaked caps(doubtful) or is it meant for preventative maintenance.
I had a psu blow once and some caps on a very old motherboard running like duron 500 mhz at the same time. or was it just the board.

I also read on a newegg motherboard page about japanese caps having 50 000 hours of mtbf, so does that mean we should recapp our stuff after 5.78 years(24/7use)?

and it will most likely keep kicking if we didn't heat damage or do anything else to them?

 

[torin3]

Yes, you can repair a motherboard with blown or leaky capacitors by replacing them. You will need to clean up any electrolyte with alcohol first though. I've repaired 3 motherboards, 2 PSUs and about 5 LCD monitors by replacing capacitors. (Though one of the PSUs also needed the bridge rectifier and some transistors replaced as well).

As far as replacing them for PM reasons, I'm not sure about that. Personally, I would wait until the board starts experiencing stablity problems, then I'd consider it if it was still a usefull system to me.

I've got to the point now that random shutdowns and stability problems first call for checking the board for bulging caps.

 

[vgta88]

i would've at least thought that blowing caps would take something else out. I think any p4 system or barton is still fast for casual pc use. (xp is pretty responsive)

I'd keep them around if i could til something can't be replaced.

 

[torin3]

i would've at least thought that blowing caps would take something else out.

It can, but it doesn't usually happen that way in my experience.

Also, if you notice they are bulging before the system won't boot anymore and replace them then, you have a much better chance of the repair working.

 

[vgta88]

It can, but it doesn't usually happen that way in my experience.

Also, if you notice they are bulging before the system won't boot anymore and replace them then, you have a much better chance of the repair working.

i think you are right. my cpu and psu weren't blown if i remember correctly nor the ram. which i find highly odd. a psu failure might take stuff out.

somehow that mobo running win 98 dx8 had a supported feature for final fantasy 7 to make it look amazing. i might revive if i could find it and know how. i also hope when my crt monitor caps go, it can be fixed.

 

[larrymoencurly]

btw the link doesn't work for me. How does recapping work?

does it revive old electronics already blown or leaked caps(doubtful) or is it meant for preventative maintenance.
I had a psu blow once and some caps on a very old motherboard running like duron 500 mhz at the same time. or was it just the board.

I also read on a newegg motherboard page about japanese caps having 50 000 hours of mtbf, so does that mean we should recapp our stuff after 5.78 years (24/7use)?

and it will most likely keep kicking if we didn't heat damage or do anything else to them?

The link worked for me, but the web page always made IE8 lock up. However it was OK with Firefox.

In my very limited experience, when devices quit working due to bad capacitors, replacing only those capacitors usually make the device work normally again, but sometimes the power transistors that feed current to those capacitors also fail, as one did on my old Socket 7 mobo. That's not to say you should replace only the bad caps, because all the other caps identical to them (same brand, type, capacitance, voltage) and that serve the same function (i.e. CPU voltage regulator, memory voltage regulator, video slot voltage regulator, or bypass filters) have been exposed to the same conditions and are likely just as worn. Many experts recommending replacing all the identical caps, wherever they are on the circuit board.

Some higher priced mobos are made with nothing but high quality caps (solid, AKA poly or os-con -- I've never seen a retail mobo made with regular electrolytics that were all Japanese or Samxon) and seem to cost as little as $75, but most mobos use 2-3 grades of quality, with the best brand installed around the CPU, the worst spread around for bypass.

MTBF isn't necessarily closely related to average lifespan because MTBF assumes that the devices don't age. That may be why hard drives made back in the 1980s had expected lifespans and MTBFs of 30,000-50,000 hours while HDs made now have MTBFs of over a million hours, but expected lifespans are still about the same. Also good and bad capacitor manufacturers both seem to specify about the same lifespan ratings, but the bad brands routinely fail ten times faster.

I wouldn't wait 5.78 years to change caps because:

1) Good caps will probably last that long without problems. For example, if rated for 2,000 hours @ 105°C and operated at 60°C, expected lifespan is

2000 hours * 2^[(105°C - 60°C)/10]/(8766 hours per year) = 5.16 years.

But cut the temp another 5°C, and expected lifespan increases by two years.

2) Bad caps in any voltage regulator circuit or next to a hot chip shouldn't be trusted beyond 1-3 years. I've had OST brand caps on ECS mobos and Fuhjyyu brand caps in old Antec PSUs bulge or pop in as little as 1-2 years. OTOH my Delta PSUs, made in 1999 with only Chemicon, Rubycon and Nichicon electrolytic caps, are still working fine, and their caps look good (sampled a few, no high ESR), and my 33-year-old TV, made by Sanyo with only Sanyo electrolytic caps, has lost only two of caps, although a non-Sanyo replacement for one of them had to be replaced.

What I do with my own stuff is leave it as-is during the warranty or return period or a year, whichever is longer, and then replace any less reputable brands of caps with good ones. I'm no expert, but I don't think this is necessary for the bypass caps that look OK (no bulging, leakage, or corrosion) and are located away from heat because I've yet to find any that measured bad for ESR or capacitance (Ltec/Luminous Town Chinese caps, OST Taiwanese).

 

[mammut]

I used Chemicon caps when recapping my EP-8RDA. 14 pieces.

Here another article: http://www.overclockers.com/index.p...ew=article&id=3652&catid=54:howto&Itemid=4260

 

[vgta88]

i think i need to practice playing around with cap soldering on the old mb i just found in the rain. i wouldn't try to learn it on anything functioning.

maybe i need some tools to test esr later on. i would not know if they break /how to change mosfets.

 

[member101]

Thank you for all the help.
Where did you buy the caps from?


Thanks,

Member101

 

[larrymoencurly]

Suppliers of low ESR capacitors:

BadCaps.net
B&D Enterprises
Digi-Key
Mouser
The Cap King
PC Motherboards Capacitor Store
Computec

 

[vgta88]

Thank you for all the help.
Where did you buy the caps from?


Thanks,

Member101

please update us on how the cap replacing goes so that we can see what issues might arise if we do the same thing.

 

[larrymoencurly]

please update us on how the cap replacing goes so that we can see what issues might arise if we do the same thing.

I don't think it's changed much since August.

BadCaps.net's recapping FAQ

Get the polarity right or the new cap will rupture within minutes or even seconds. Connect the "-" of the cap to "-" on the circuit board, the "+" on the cap to "+" on the board. Most boards mark the "-" side with a half-circle marked white or black, with either solid paint or with diagonal stripes, but Asus and Asrock are rare exceptions, and the half-circle indicates the "+". Check which way the original capacitors were installed before removing them.

Make sure replacement caps are are rated for at least as much voltage, capacitance, temperature, and ripple current as the originals, but also get the diameter right (some boards can't fit anything even 1mm fatter) and be sure the height isn't excessive (especially for caps that go between sockets or are inline with plug-in cards).

You need plenty of heat, at least 40-45 watts, or the solder will take so long to melt completely that board damage will likely occur first. The FAQ describes how to remove caps and clear out solder from the holes.

You can probably always get away with using Sanyo WG, Nichicon HM, HN, or HZ, Rubycon MBZ or MCZ, Panasonic FM, Nippon Chemicon or United Chemicon KZE (experts say their KZG and KZJ series fail) caps.

Inspect your work with a magnifying glass, both before and after installing the new cap, for damage to the copper traces and any solder shorts.

 

[Mellon Head]

I think I'll chime in with some free advice since I do this for a living, but read the FAQ too.

1. Buy the best caps you can afford. A solid electrolyte is probably the best bet if you're looking for endurance, but they don't come cheap, and they can be tricky to find. Also, buy the shortest and smallest caps you can get, for clearance reasons.

2. Most motherboards built in the past few years use a lead-free solder process to conform with environmental regulations. It takes more heat than you might expect to get them out. Motherboards are also multi-layered, and too much heat can separate the layers of the board, breaking the connection between the layers.

3. It's very easy to destroy or lift the pads during the de-soldering process. Take it slow and easy, and don't try to force the cap out of the holes. Instead, rock the cap side to side, and back and forth gently after you have used a solder removal tool, like one of those vacuum suction tools. (About $30 at any decent electronic supply store.) If it won't come loose, try a little heat on one leg while pulling the cap gently and ease the lead part way out. Then do the other side. Repeat until the cap comes out.

4. The easiest way to remove a cap is to apply heat to both pins at once, and gently rock the cap out of the holes. Then use a vacuum tool to remove the left over solder. This may require help from a buddy with another soldering iron. Save the beer for AFTER you've fixed the board.

5. Putting the caps back in is pretty easy. Make sure you get the polarity right, and the spacing of the cap leads. I leave the leads long as I solder, as it helps to draw a little heat away from the board, preventing further heat damage. I also wouldn't use lead free solder for this. It takes more heat and some practice to use, and you might wind up making "cold" joints, and the mobo may still not work. A decent 60/40 resin core solder is just fine.

6. After everything is soldered, check your work for shorts and snip off the leads as close to the board as you can with some decent wire cutters. Clean the areas that were soldered with some isopropyl alcohol and an old toothbrush, making sure the leftover resin is gone. Let the board dry.

7. Before sticking in that RAM and megabuck i7, power the board up and see if anything pops or sparks. If you have a Volt meter and know where to measure, see if your 12V, 5V, and 3.3V are stable, and feel around to see if anything is really hot. If there are problems, check your work again to make sure there are no shorts, and nothing is in backwards.


It isn't hard to do, it just takes a little time and patience. A recent board took about an hour for me to do 14 caps. I have almost 20 years experience at this. It will take you longer, but that's okay, the reward is having a good motherboard again, and it feels real good to say "Look what I did." over a cold one.