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PCs Plagued by Bad Capacitors
Hawaiian Rules writes "CNET has a story
detailing a new threat to Dell PCs, Apple iMacs and other computers with Intel boards. This has been documented on BadCaps.net for some time, but the article also discusses what to do if you suspect you've got a case of the bad caps."
Bad Caps have been a problem since 2002 at least. For awhile, I was making some bucks repairing Apple Airports, with all their bad caps.
I drank what? -- Socrates
I had this happen to an old Asus board I had a couple year ago. It was covered on /. before.
Slashdot - Taiwanese Capacitors Leaking, Exploding
Watch out for all the 'Geeks popping a cap in your mother' jokes.
-Eric
You can read the whole history of dying iMacs on Macintouch.
Strange women lying in ponds distributing swords is no basis for a system of government.
Ok, I realise most people (in general, not the /. population) probably wouldn't know which end of a soldering iron to hold, but it's not that hard to fix the issue..
Read the values of the leaky caps, get replacements, or near enough in value replacements. This will probably cost about $5.
Desolder the old caps, use a stainless steel pin to clean the solder out of the hole (since solder won't take easily to stainless), pop the new cap in (with the correct polarity), and solder it.
I had an asus board go like this a couple of years ago, it took me about 1/2 hour to fix the issue, but most of that was getting the board out of the case, and reinstalling it.
I called up asus, and had a runaround, before I identified the caps as the issue, and decided to fix it myself.
I doubt it's going to cost $300 million dollars to fix this. I'm typing this on a GX270, and it's had the motherboard replaced in it already, but I don't know if caps were the reason for that.
It's my work machine, first the hard drive died, so I called Dell and got it replaced, then the mobo died, and I just called Dell and got it fixed, I didn't investigate the issue myself, like I would have done if I owned the equipment, or if it was out of warranty.
Anyway, while it might cost them a bit in labour, the hardware's not going to be all that much, replace the first few boards with working ones, then refurb the retrieved boards, and use those to replace the dodgy board, rinse, repeat.
The problem with the Airport base station capacitor failures is described on this web page:
http://www.vonwentzel.net/ABS/Repair/
There are also instructions buying and replacing the failed parts, with good images. I followed these instructions a couple years ago very successfully.
The article says that the caps have "... a letter "X" stamped on the top." They are not stamped with the letter "X" - they are stamped to allow the caps to deform and vent the boiling liquid contents in a predictable manner when it fails. That is why the top of a failing cap bulges and not the sides.
..
Not that it always works - plenty of caps still just "pop" violently and spew their content across the electronics anyway.
So don't look for a stamped "X", chances are all your caps have them
The caps were made by Nichicon. Nichicon has been in business for 50 years and has had, up to now, the reputation of building *the best* low esr high quality electrolytic caps on the market. I've specified Nichicon caps only in designs because they work better than anything else.
That's why this is such a surprise.
I know it's bad form to bitch about moderation, but I can't see any way that the parent is insightful. Nichicon has produced good caps for years. Manufacturers pay a premium for Nichicon caps. Something or someone fucked up a Nichicon. Has nothing to do with trial and error.
"Eve of Destruction", it's not just for old hippies anymore...
But that's not what happened. The capacitor company in question, Nichicon is, or rather was, the best in the business. Manufacturers pay a premium for Nichicon caps because they were the best available. The motherboards in question were made by Intel and Intel uses quality parts.
The problem is that Nichicon screwed up somehow, not that Intel got burned for buying the cheapest parts.
"Eve of Destruction", it's not just for old hippies anymore...
I work at a university where we purchased hundreds of the Dell GX270 a couple years ago.
;) of a GX270 as they can manage. It would be interesting to see the results of a class-action against Dell suggesting they are violating the warranty agreement because of this. Their refusal to even try to honor their NBD warranty service doesn't instill much confidence in those of us responsible for purchasing.
Well look at that. We're not alone in the world after all.
My workplace also purchased a whole bunch of GX270's a while back, and we too are having them fail on us at an impressive rate. It's interesting because I always thought that Foxconn motherboards (what Dell uses) were pretty reliable and well made.
The crappy part is that we have all these systems under same-day warranty, but because they are backlogged with so many claims to replace the motherboard, our warranty service has also turned into something more along the lines of a three-weeks-later warranty. This really pisses us off because we paid a lot extra to be able to get stuff repaired immediately.
Personally I think that if Dell cannot replace these motherboards because of their own faults, they should still have to meet warranty expectations even if it means sending us a brand new system as close to the capacity (no pun intended
"What do you despise? By this are you truly known." --Princess Irulan, Manual of Muad'Dib
/)
The definitive study, from The Computer Aided Life Cycle Engineering (CALCE) Electronic Products and Systems Center , is "Identification of Missing or Insufficient Electrolyte Constituents in Failed Aluminum Electrolytic Capacitors". CALCE actually took capacitors apart and analyzed the electrolyte.
To see if the excessive hydrogen was being produced by impurities in the capacitor foil, wavelength dispersive x-ray spectrographic (WDS) analyses of foils from a capacitor from the lot of Taiwanese capacitors known to bulge and foils from a capacitor from a lot of non-bulging Japanese capacitors were performed.
A small amount of magnesium was detected in both the Taiwanese and Japanese foils, and copper was detected in the Taiwanese foils alone (see Table 1). Ignoring the topical constituents of oxygen and carbon, the purity of the cathodic aluminum foil from the Japanese capacitor worked out to be approximately 99.1 wt%, which was within the limit set by Dapo. The purity of the cathodic aluminum foil from the Taiwanese capacitor was approximately 97.5%,which was below the minimum value stated by Dapo. The insufficient purity of the Taiwanese aluminum foil could cause gaseous hydrogen production that would not be impeded by a depolarizer, but the galvanic couples were not thought to be sufficient to account for the rapid production of hydrogen gas that was necessary to cause the relatively rapid bulging of the capacitor cans. There were other anomalies in the ion chromatographic analyses,chiefly variations in the amounts of ammonium and phosphate ions present. Ammonium ions in water form ammonium hydroxide, which is strongly basic. This raised concerns about the pH of the electrolyte in the bulging capacitors,as a review of the chemical properties of aluminum oxide - the dielectric - showed that it is slightly soluble in basic solutions (but not in acidic)[8 ]. Measuring the pH of electrolytes from capacitors from the Taiwanese lot known to bulge and from a Japanese lot that had not exhibited bulging showed that the electrolytes of the bulging lot were weakly basic (7 < pH < 8),while those of the non-bulging lot were acidic (pH 4).
And that's the cause - internal corrosion because the electrolyte has a highly acidic Ph.
Maybe heavier means more durable, I dunno, but I don't carry my 42" plasma TV everywhere. I leave mine in my living room, so don't care if it's built like a brickhouse.
We bought six identical iMac G5s, plus two of us bought identical systems for our homes. Out of the batch of 8 machines, we have:
n program/).
1. Replaced the motherboard in two of these machines.
2. Replaced burned power supplies in one of these.
3. A third machine burned both the motherboard and the power supply. It has taken Apple over a week to ship the parts to be replaced.
Al repairs so far have been under warranty. Half the service transactions have been done thru the genius desk, half thru Apple Care. Both methods are painfully slow.
Also, on the iMac G5 Apple will extend coverage specifically for the capacitor issue, so even if your warranty coverage expires they will fix your machine at their expense (http://www.apple.com/support/imac/repairextensio
Pedro
----
The Insomniac Coder
... the most important thing to remember when buying Dell computers:
Don't
"Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
120*sqrt(2)
- You're really sure you have bad capacitors.
- You have successfully removed capacitors from a board before.
- You have the right tools:
- A fine-point soldering iron, 47 to 150 watts. NOT your typical 20-watt pencil iron.
- A solder-sucker.
- Known good capacitors:
- Not from Rat-Shack.
- Not salvaged from a dead car stereo
- Same uF.
- Save Volts
- Rated for HIGH RIPPLE CURRENT.
- Rated for 85 or 105 degrees C.
- A grounding strap for your body and soldering iron.
- Willing to take the 25% risk of killing the mobo anyway.
The reason for all these cautions is that mobo power supply capacitors are highly stressed-- those square black FETs are hitting the caps with 30-amp pulses about 200,000 times a second! Your basic Radio-Shack 49 cent capacitor can't handle this kind of stress.(Best bet is to order them from Digi-Key, they list the full specs.)
You also need a big honkin' soldering iron as each of those capacitor leads are soldered to many layers of copper foil, which make excellent heat sinks. It takes 50 to 100 watts of heat to heat up all those layers in an expeditious fashion.
I would first practice this art on an old scrapped motherboard. A true geek always has a few of these around. Practice your unsoldering technique until you can get a capacitor off (no jokes pls) in 20 seconds with no damage to the board.
Don't ask me how I learned all the things not to do.
Anybody want to buy a few "as-is" mobos?
Nichicon appears to be the only company manufacturing those short (~5mm high) axial capacitors, and our repair facility had to order them directly from Japan, as I wanted the 105 degree C rated caps, in contrast to the 55C rated caps that were installed in the radios. In South Florida, you could easily get in-dash temperatures over 200F: 90F air temperature outside the car, sunny day cooking the inside of the car.
More fun than blowing them up is to charge them and toss them at someone while saying 'catch'. Even more fun is getting a coke can sized one and welding things together with it (you can only get a little spot welded, though - perfect for carraige bolt stick men).
Or better yet, wire one to the inside of a door handle and charge it up. Man, I never thought my grandma could jump so high....
If this can be lethal, please mod this post up informative.
If this is post is modded up, be careful! Doing the quoted things can kill people.
Safety first!
- -- Truth addict for life.
" Doing the quoted things can kill people."
That's correct. Never, never play with charged capacitors. Except for the carraige bolt stick man and popping big ones, I was just kidding.
"We are all geniuses when we dream"
- E.M. Cioran