Blown capacitors - can it be caused by a bad power supply?

[davexnet]

Hello -
I replaced 6 capacitors close to the cpu/fan which had originally bulged/leaked.
I did this work about a year ago. The computer has become slightly unstable
in the last week or so. I opened the case and I see that one of the capacitors
I replaced has bulged quite badly and has brown gunk on top of it.

I'm wondering if the power supply is in some way to blame.
It's an Antec True Power Trio @430 W. It sometimes feels quite warm at the back,
not sure why. It's a pretty modest system - can't be that much power draw?

2 hard drives, 2 DVD-RW's, one EVGA 8600GT graphics card - that's it.

[johns0]

The capacitors were cheaply made and used in thousands of electronic devices and have caused the same problem,now motherboards are stating on the box that high quality capacitors are being used.

[aedipuss]

more likely the bad caps damaged a rectifier when they went, and the new caps are over stressed.

[johns0]

Still could be you replaced the caps with cheap ones,what quality are they?

[davexnet]

I'm pretty sure they were Rubycon MBZ, according to my records.
From an Ebay source in Hong Kong.

I've got a couple left over - perhaps I should transplant the one and see what happens.

SO my theory about the power supply being a potential source of the problem is unlikely ?

I got just over a years use out of these caps before the problem came back.

[aedipuss]

if the p.s. were bad it would take out everything.

[MJA]

try to use Panasonic caps from http://www.digikey.com/

[Constant Gardener]

Check the temperature ratings of the capacitors; higher is better. Try a quality supplier such as Digikey. I had leaking capacitors in my circa-1975 stereo, so I replaced them with higher-temperature versions, and they've been fine for fifteen years now.

[MJA]

http://badcaps.net is good site for help.I got few good tips from those guys when my Samsung DTBH260F went bad


btw.is your motherboard made by Abit?

[aedipuss]

http://badcaps.net is good site for help.I got few good tips from those guys when my Samsung DTBH260F went bad


btw.is your motherboard made my Abit ?

i loved abit boards. too bad they sold the motherboard manufacturing devision. i have a couple ip35 boards that had the tightest voltage regulation and o/c ability around.

[davexnet]

The motherboard is 4 years old, a Biostar Nforce 410/Geforce6100 M9. Perhaps the best bet is just replace it with another
socket 939 board (if I could find one). That way I can use the existing CPU and RAM.

The caps are rated at 105 degrees. I've touched them with the box running, they're just warm at the most. So it's not heat
destroying them.

Thanks for the reminder about badcaps.net - I just took a quick look at their forums. There's a link to some youtube
video's showing everything you could ever want to know about soldering .

SO at this point, the PC is still usable. Interesting how this one cap is quite severely bulged, while the others
that I replaced, all in a line, look brand new.

[turk690]

The motherboard is 4 years old, a Biostar Nforce 410/Geforce6100 M9. Perhaps the best bet is just replace it with another
socket 939 board (if I could find one). That way I can use the existing CPU and RAM.

The caps are rated at 105 degrees. I've touched them with the box running, they're just warm at the most. So it's not heat
destroying them.

Thanks for the reminder about badcaps.net - I just took a quick look at their forums. There's a link to some youtube
video's showing everything you could ever want to know about soldering .

SO at this point, the PC is still usable. Interesting how this one cap is quite severely bulged, while the others
that I replaced, all in a line, look brand new.

I routinely replace electrolytic capacitors in industrial and consumer electronic equipment PSUs. Though I use 105°C capacitors all the time, some of them fail again. I'm told that there are fake Rubycon and Nichicon brand capacitors out there; one way of telling is the notoriously bad-quality printed info on the plastic sleeve that envelops the capacitor itself. Another brand to avoid at all costs is the China-made Multicomp, which is sold even by you would think reputable sellers like RS and Farnell. If capacitors in question regularly fail (within months) and they have been replaced by another brand or model, it's really probably that hot in that spot they are occupying on the PSU. (Or you could pay more bucks and try 125°C capacitors by Philips.) It's also possible the main rectifying diodes that feed them are themselves leaky and do not efficiently block the intended polarity completely (unless designed specifically, electrolytic capacitors are completely unforgiving of wrong polarity).
IMHO electrolytic capacitors are the Achilles' heel of most modern electronic equipment. They are nearly always the first to fail. They are the product of that quest for the highest amounts of capacitances in the smallest possible volumes, and the quickest route has always been to up the K constant of the dielectric by including the electrolyte, which is a liquid that sizzles and boils even as it merrily filters off the >200KHz of switching noise your Antec makes. Some mainboard manufacturers (Gigabyte) have made a big do about solid electrolytic capacitors (nothing to evaporate, and by implication will not fail??), but I haven't come across any major reviews refuting or corroborating their claims. In the meantime, part of my livelihood is replacing electrolytic capacitors galore, so there...

[davexnet]

I may try the cap swap some time soon. I had experienced some instability, a couple of BSOD's in XP, and
video hardware driver recovery errors in Vista - I now think it was due to the Nvidia 280.xx drivers. Seems as if plenty of
users have had similar problems, as can be seen in the Nvidia forum.

Except for those, the PC is behaving normal, regardless of that obviously blown cap.

[pandy]

I'm pretty sure they were Rubycon MBZ, according to my records.
From an Ebay source in Hong Kong.

You have answer - fraud electronic components (both passive and active) are serious problem - use only reliable source for components. Check power lines with scope for current quality (very high voltage peaks) however IMHO issue is with components not with power supply.

Take seriously advice from turk690, if You still want to have additional protection, check capacitors with ESR meter- something like this for example http://kaspars.id.lv/?menu_id=32

[davexnet]

pandy, I didn't know about the US suppliers until later. I found the caps on Ebay offered by a seller with 100% feedback score.
I don't have an ESR meter, perhaps something I can look into
(especially since I have some of his caps left over - I bought two sets).

I really dread having to work on the board again. The reason is, on the reverse side of the board where the solder goes,
you poke the leg of the cap throught the hole, and you're supposed to solder the leg to the small
metallic circle surrounding the hole - well the circle has disappeared, so I don''t know what I'm soldering it to.
Perhaps within the hole itself is the remains of the connector. I don't think the board will survive another attempt.

[pandy]

Ok, but one of recommended methods to replace the caps is cut old caps (not bend but use proper tool to cut them), leave (1 - 2 mm is enough) remaining cap wires (pins) in holes(solder pads), solder new capacitors to those remains pins (You avoiding situations when low thermal capacity solder rip of via's/holes metalization) - for easy unsolder some hot air solder station is better (heat bigger area - mostly ground plane to avoid breaking metalization), some people in servicing work use so called preheaters http://www.youtube.com/watch?v=fpj-nIVTaHs - whole PCB is heated to for example 100C deg - then solder is able to heat selected point more efficiently thus avoiding uneven heat distribution and in effect ripping off board pins from non-melted solder pads.

[TBoneit]

I'm pretty sure they were Rubycon MBZ, according to my records.
From an Ebay source in Hong Kong.

I've got a couple left over - perhaps I should transplant the one and see what happens.

SO my theory about the power supply being a potential source of the problem is unlikely ?

I got just over a years use out of these caps before the problem came back.

Many, many fakes on eBay.

The ones in a row near the CPU are in parallel. The one that has failed is putting additional stress on the others shortening their life.

[davexnet]

[QUOTE=TBoneit;2116352]

I'm pretty sure they were Rubycon MBZ, according to my records.
From an Ebay source in Hong Kong.


The ones in a row near the CPU are in parallel. The one that has failed is putting additional stress on the others shortening their life.

Thanks for this info. I'll take a look this weekend.

[lacywest]

The motherboard is 4 years old, a Biostar Nforce 410/Geforce6100 M9. Perhaps the best bet is just replace it with another
socket 939 board (if I could find one). That way I can use the existing CPU and RAM.

The caps are rated at 105 degrees. I've touched them with the box running, they're just warm at the most. So it's not heat
destroying them.

Thanks for the reminder about badcaps.net - I just took a quick look at their forums. There's a link to some youtube
video's showing everything you could ever want to know about soldering .

SO at this point, the PC is still usable. Interesting how this one cap is quite severely bulged, while the others
that I replaced, all in a line, look brand new.

Unless you did post the link ... I'd be interested in that YouTube link ... I've been to Badcaps dot com and they have a kit of capacitors for my MSI mobo ... it is in the K9N6GM family of mobos ... has 4 rows for DDR2 memory and Firewire and 6 audio outputs. Worked just fine and started freezing up and stuff ... looking closely I saw 2 capacitors that appeared ... fat on top.

When I got the mobo out ... 10 capacitors were swelling ... type >> 1800uf ... 6.5 volts. When I took out the MSI mobo ... I put in a Abit AN-M2 instead.

This MSI mobo ... I really dont want to throw it away ... and my soldering skills are good ... been soldering stuff for years and years.

Read some where about the circuit board having some kind of design where the holes are that the capacitor leads go into. Something about ... if it is a sloppy solder job ... the holes where the capacitor leads go through will be screwed up and render the board useless. There is supposely a tube of some sort ... as the hole itself where the leads go through ... something I did not know.

Any thoughts on this ??

[davexnet]

Sure, here is part two, parts one and three are also on there.
http://www.youtube.com/watch?v=fYz5nIHH0iY&feature=relmfu

[turk690]

Read some where about the circuit board having some kind of design where the holes are that the capacitor leads go into. Something about ... if it is a sloppy solder job ... the holes where the capacitor leads go through will be screwed up and render the board useless. There is supposely a tube of some sort ... as the hole itself where the leads go through ... something I did not know.

Any thoughts on this ??

Most current mother boards (MOBOs) are sophisticated multi-layer printed circuit boards (PCBs). There can be 4 layers or more, and conduction between these layers happen with plated-through holes, or vias. Some of these vias are just there to join circuit traces on different layers; some also happen to be the terminals where the leads of through-hole components (such as your notoriously favorite electrolytic capacitors) are soldered in. In the latter case, during the wave soldering portion of manufacture, these terminals with the component leads in them are heated to just the right temperature for the right period of time to ensure a reliable joint. You have to realize that in many places on the MOBO, big swathes of copper traces are simultaneously heated in this way, and this is not always reliably replicated in a stand-alone situation where attempts are being made to replace the bad capacitor. When excessive heat and pressure are applied, the solder pad can be torn off and the via connecting the different layers pushed out. On one extreme, yes it CAN render a MOBO dead. But in my experience, the electrolytic capacitors that die are more often than not in groups of 4 or more in parallel, such that as long as ALL of them are replaced (not just those that are visually defective; the part where the solder pad was torn off can be left unpopulated), the MOBO can work again.
This sounds simple but can be MUCH MORE complicated in reality. For example, you will need a temperature-controlled soldering iron with a a tip that is large enough to reliably heat the via and the traces associated with it, but small enough not to damage nearby unrelated parts of the MOBO. All MOBOs are now lead-free (proudly marked RoHS), and the higher melting points of these Sn-Cu alloys (>>350°C, compared with <<320°C for conventional 60/40 Sn-Pb) complicate the repair even for people like moi (what more for those attempting to emulate the YouTube tutorials?).
Some very high density MOBOs with 6 layers or more probably can't be repaired in a domestic setting. But I'll look at it this way: maybe it's now time to up the ante and buy a 2011-socket Intel X79 chipset MOBO. You can then set aside issues about defective, foul-smelling, blown electrolytic capacitors for the time being.

[pandy]

Guys, people preheat board for repair - heat is so quickly removed from solder tip by multilayer PCB that even 60 - 80W solder is sometimes not enough - thus we need to pre-heat the PCB - for example to 80 - 100C deg.
Some people buying special pre-heaters but some people use electric pans or special electrical portable warming plates to keep warm food on table - they are inexpensive - between 20 - 60$ (more expensive are IR heaters).

[lacywest]

Badcaps dot come offers a service for 70 bucks to replace the bad caps ... I did not pay that much for the MSI mobo and it was soon at New Egg ... not available ... it is ... was there ... to be bought but not anymore.

Here are some pix of the bad caps ... 1800 uf ... 6.3 Volts. ... I have some ACER PCs with their mobos out ... they use the same exact capacitors ... and they are not swelling ... I wonder if I can use them. Or should I just get some new capacitors ... at >>> www.badcaps.com ???

[lacywest]

Guys, people preheat board for repair - heat is so quickly removed from solder tip by multilayer PCB that even 60 - 80W solder is sometimes not enough - thus we need to pre-heat the PCB - for example to 80 - 100C deg.
Some people buying special pre-heaters but some people use electric pans or special electrical portable warming plates to keep warm food on table - they are inexpensive - between 20 - 60$ (more expensive are IR heaters).

So ... should I wait until next summer ... and do the repair job in 105 degree weather ?? I am actually serious !!

Hmmm ... I'd be sweating ... how about a nice warm spring day ... around 90 degrees outside ... or in my garage.

[pandy]

http://en.wikipedia.org/wiki/Celsius

thus we need to pre-heat the PCB - for example to 80 - 100C deg.

[aedipuss]

you can still get am2/am3/am3+ motherboards. this one has 4 ddr2 slots, the only thing you'd need to add is an add-in firewire card.
http://www.newegg.com/Product/Product.aspx?Item=N82E16813157226


a couple of board soldering hints. never use an iron with over 15 watts power, you will always lift/kill the solder pads on the board and possibly burn the traces inside the board. lots of flux and a copper solder wick will remove all the solder from the holes. never pull anything out while it's hot. wait and see if you have removed all the solder first. if you have the wires will be free and you won't destroy anything removing the bad part. don't rush anything there is no repairing lifted pads and burned traces.

[davexnet]

When I did mine about a year ago, I left a bit of wiggle room in case any of them should subsequently go bad
(one has). Instead of mounting them flush to the board I raised each one about about 1/4 inch above the board.

My plan at this point is to cut out the bad cap and leave the 1/4 inch of leg and solder the new cap to those old legs.

When I did the caps, I tried first with a lower powered iron; it wasn't hot enough to melt the solder. Seems as if the board
was just sucking the heat away. I wasn't getting anywhere, couldn't get the old caps out.
Had to go with 25W. As I mentioned before, it's questionable whether the solder pads were there after the old caps
were taken out. If they were, they were very small - However, I assumed the eventual outcome was OK since the new
caps did solder in OK and the board was operational.

I think the best bet, is to go with a temperature controlled iron as can be seen in the youtube video.

I thought about a new board. A few cut price am2/am2+ can be found, as you mentioned,
they have one for $29.99 at evga.com b-stock. In my case, I'd have to get a new cpu + memory to go with it.

[turk690]

Badcaps dot come offers a service for 70 bucks to replace the bad caps ... I did not pay that much for the MSI mobo and it was soon at New Egg ... not available ... it is ... was there ... to be bought but not anymore.

Here are some pix of the bad caps ... 1800 uf ... 6.3 Volts. ... I have some ACER PCs with their mobos out ... they use the same exact capacitors ... and they are not swelling ... I wonder if I can use them. Or should I just get some new capacitors ... at >>> www.badcaps.com ???

You do not have to be strict with the values of the capacitors to be replaced. For example, those 1800μF/6.3V capacitors can be replaced with 2200μF/10V, which is more common. The 6.3V rating means it's most likely decoupling the +5Vdc or +3.3V or +1.8V line of the MOBO circuitry. Other exotic values like 820μF and 1200μF can safely be replaced with 1000μF. It's silly considering the exactness of the number 1800 when the actual capacitance can vary over a range of +50%, -20%. That's how loose electrolytic capacitor values are. It's not extreme for me to say putting a 2200μF in place of a 1000μF or v-v of the same voltage and temperature rating will hardly cause that MOBO to miss a beat. It may or may not be that the 1800 value is there to throw off non-pros, go figure. The other major voltage in a MOBO is +12Vdc, which will be decoupled by 16V or 25V capacitors. All the capacitors to be installed should be 105°C or more. I concede that, that we are swimming in a sea of fake or (deliberately) wrongly-labeled capacitors does not help. But there are ways of avoiding them. Of course if you've used them in the past to replace bulging capacitors just like the pix above depict and the replacements also bulged even sooner this time (or outright exploded and made the MOBO dead), then you know what NOT to buy. One brand to avoid if it's the last Farnell or DigiKey sells is MultiComp. I have desoldered capacitors that have brand names like HsiLueh, Power Gong, RedVox, and TopCap; frankly, if the name is a tongue-twister and sounds like it came from north of Guandong or Shenzen, China, or it's too cheap the lot is weighed instead of being sold per piece, then it's too good to be true and you shouldn't be caught dead with it. Sadly, casual inspection of catalogues of such august stockers like RS, Farnell, DigiKey, Newark doesn't tell much if those capacitors on offer will survive well after 21 December 2012 or whose electrolyte begins to evaporate even while in transit to you. I suppose my intuition has been honed by years of experience. But that's what you pay people like me for. Either that or get the new X79-chipset socket-2011 MOBO...

[pandy]

a couple of board soldering hints. never use an iron with over 15 watts power, you will always lift/kill the solder pads on the board and possibly burn the traces inside the board. lots of flux and a copper solder wick will remove all the solder from the holes. never pull anything out while it's hot. wait and see if you have removed all the solder first. if you have the wires will be free and you won't destroy anything removing the bad part. don't rush anything there is no repairing lifted pads and burned traces.

Always use proper wattage iron - sometimes this is 60 - 80W , sometimes 15W - most important that soldering iron must have temperature stabilization, 15W is OK but only for SMT and only when no large area of copper is heated - it is common misconception that small iron is safe - no - sometimes is worse - now on market there is lot of soldering irons with electronic temperature stabilization - most of them are 60W and those irons are very good for PCB repair.

If someone have problems with soldering there is a special low temperature solder (brand name Chip Quick) http://www.youtube.com/watch?v=7kyaz4Zrd78 - it will help people to make work without damaging PCB.
http://www.chipquik.com/

[tigerb]

I watched the videos and this seems like something fun to do/learn...can you guys recommend a place where I can buy all the tools as shown in the video?

Thanks.