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Faulty Low-ESR Aluminum Electrolytic Capacitors
Has anyone here seen concrete examples of this "phenomenon"?
This site claims that there was a fairly large scale supply problem with Many Major manufacturers unknowingly getting defective capacitors.
http://www.logic1.ca/Tips.htm
Yeah, if memory serves, we had a rash of A-Bit motherboards going bad because of faulty caps.Quote:
Originally Posted by The_Silent_One_1
old news.
were probaly seeing hte effects of it now as this equipment nears the life expextancey of these parts.
Havent been buying tiwanees caps for 1 1/2 years now. (or products that use them) drives sales men nuts: Prove the origin of all capacitators in this unit or I wont buy it. realy limits my component choices, but I have peace of mind that it will work for a long time and be reliable.
Lots of examples yes!!!! If I remember A-bit was the only company to admit there was a problem and offer to replace the boards.....
Not large numbers, but recently did a batch of MSI boards for a local computer store.
still dealing with them. Just got 6 ecs board in all with faulty caps. SO far I have seen it on all the boards we sell; ASUS, Abit, MSI, ECS, Gigabyte, and Tyan
I first heard of it about 2 years ago. To give you an idea of the timeline...it was when A7V133 mainboards were still being produced. We had faulty boards from Gigabyte, Asus, Abit etc.
Joe
Actually, shuttle did as well, we RMA'd about 45 of them. AV11 I believeQuote:
Originally Posted by Shard92
I just mailed a Gateway Profile4 (bought Spring of 2003) back for service that had two blown capacitors (near the CPU heatsink). First ones I'd ever seen.
I saw my first photos of this about a year ago, so I new what to look for. It was obvious: charred crust on top of each, and crust underneath one also. That latter one almost came off the motherboard.
@FireAm94 please don't scare me. I just rebuilt my ASUS A7V KT133 computer with WinXP and it's humming like never before. All I need now is for it to give up its ghost! :sad: I think I'll do a pre-emptive examination to see if anything is starting to fry.
most of the caps involved in this ( if not all ) had a "+" on the top. I don't remember ever seeing ones of other configurations have this problem.
Ironically Enough, There was a Gigabyte board in my office that had some "weird" problems trying to fresh install O.S.'s that I finally decided to examine and low and behold, about a dozen capacitors had little "rust spots" on the top of them.Quote:
Originally Posted by Shard92
Does anybody know how easy it is to replace those?
Quote:
Originally Posted by The_Silent_One_1
far more difficult than replacing the motherboard. Have you had much experience with soldering? One problem ( and feel to correct me if I'm wrong ) is motherboards are multilayer so it's difficult getting it to make connections on all layers.. Might be fun to try if you have some experience in that area AND the motherboard was used for non-critical home use, but I wouldn't recommend it for the inexperienced or for a business machine...
It's currently in my hard drive tower. Because of the inability to install an os on it, I've relegated it to running hard drives for disgnostics or Secure Wiping. So, it'd be no great loss if it ceased working at all afterwards.Quote:
Originally Posted by Shard92
The trick to soldering replacement capacitors on a motherboard, if there's room, is to not try to desolder the old capacitors. Instead, destroy them with pliers so that the old wires still poke up. Then solder the new caps to the old wires. Looks ugly, but it works.
I wouldn't be inclined to do this. If some caps are bad, others might be also. Most motherboards have caps too close together andyway and this would be a very difficult job.
Yep the bad caps have a +
Gateways - any with a jabil motherboard they have the + caps 3 next to the processor pop at least gateway extended the warrenty out to 3 years on the workstations affected. every single gateway we have that is more then 1 yr old and has a 1 ghz or faster processor has had the motherboard replaced. 200+ the old select 350 - 600 MHZ boxes are still rock solid and they are older then dirt.
SoYo dragons 12 diffrent caps all over the board
There was a maximum PC article about this issue a while ago ill have to dig through and see if I cant find it.
I've succsessfully replaced capacitors in many different brands - mostly ABit, MSI, Soyo, PCChips/ECS, IBM, last MB was from AOpen... I suspect most of those failures were rather caused by cheap PSUs, though... As a rule - if you see MB with popped capacitors, you'll see the same defective capacitors inside the power supply ... Open the PSU's case and check it out... Just only replacing motherboard will not solve the problem - you'll have to replace the PSU as well...
It is not a big problem to re-solder capacitors - just only some soldering skills are needed for that...
Wow! That supports the theory that I've held for some time that You are better off to use a brand-name Power Supply.Quote:
Originally Posted by Ruslan
Can anyone else corroborate this occurence?
Yes, name-brand is much better than cheap. Someone told me that a cheap 430watt power supply is only as good as a 300watt high-quality PSU. I think that isn't a totally accurate statement because a bad power supply is worse than that, and I've had cheap power supplies that were excellent. The thing is, with expensive PSU's they have better quality control. You pay extra for the reduction of failure. With a cheap PSU, you could get anything from great to disaster.
Someone else, though, told me that when you buy a cheap PSU, it helps to buy one with maximum watt rating. If you have a 500watt PSU and only load it with 350watts, even a cheap PSU is less likely to fail.
The only problem with this is that sometimes even the name-brands have short runs of very bad production before they catch the problem.
What fun. On top of all the other things that can break with software, you have a minefield of hardware issues to worry about.
Yeah, I just blew out an Enermax 470 Watt Noisetaker ATX 1.3 Power Supply that was 3 months old. I traded in the warranty replacement on a 550 Watt Antec True-Power P.S.Quote:
Originally Posted by JeffO93
Thorian, the capacitors in question are electrolitic capacitors, and they are polariized... they have a positive and a negative terminal. All of the caps I've seen have the negative terminal marked with a minus(-), the positive terminal is unmarked. Are you saying that the manufacturer was so inept as to mark his caps with a (+) instead??? As well as being substandard, they are readily identifiable by sight????
I've had a few mainboards with the domed caps come through here, but I've just tossed them. Next time, I'll look more closely.... very interesting!!
Just saw this.
Intel CPUs put pressure on capacitors, claim
Mobo makers considering switch
http://www.theinquirer.net/?article=20309
The original problem was much different however. They were pretty much garunteed to fail....AMD or Intel. You would think QC would actually care about these products....but apparently not.
Joe
Was just gonna post that bit of news here techs, maybe ppl will think u were me, and I get credit! j/k
I've never seen bad caps, heard a lot, read alot, chatted alot, but never seen. I'm just hoping it never happens to me, No Soldering Skills here ;)
Quote:
Originally Posted by dfritz
They are not a mismarked pole. the top that domes out the ones I have seen that have failed are stamped with a + (divided into 4ths) the boards that we were recieving for warrenty repair had a mercedies emblem (divided into thirds) stamped on the top. ( those were the gateways) the Soyo Dragons we replaced also had caps that the domed top was stamped with a + where as the caps that had a 1/2 hexagon pattern were fine.
Could be anicdotal evidence but I found it odd that the bad caps all had a + on the top (part that bulged out, not the terminals)
Quote:
Originally Posted by thorian
Yeah I don't know if it was a cooincidence or not but all the ones I've seen are like that as well.....
I've never seen any caps soldered in wrong polarity so far... ;)
I think the issue is rather connected (as we already know it) with stolen formula... Another possible causes, IMHO, are:
1. Low-quality cheap power supplies. I'm not surprised what almost in every case with bad capacitors on MB there were also some bad capacitors inside the power supply... See for yourself next time you'll have customer's bad PC with blown caps...
2. Heat (usually blown caps are located near heat-emitting devices like power transistors).
Ohhh! I just had a look at a board. One had "k" on the top of every cap, another had "+" on the top of every cap. I have stood on my head, used mirrors and flashlights etc. to read the capacitance and voltage and polarity, but had NEVER noticed the mark on the easiest part to see was different.Quote:
Originally Posted by thorian