I heard a loud bang the night before last and upon investigation, it looks like one of my capacitors on my video card exploded. The card still works okay.
I figure I still have a couple of good caps left, but once those blow, the card will be shot.
What causes caps to blow? Is there anything I can do about the blown one and to prevent the others from popping?
Or should I junk it and buy a new card?
<Deforrest Kelly>
It’s dead Jim.
</Deforrest Kelly>
The electrolyte in capacitors tends to dry out causing the capacitor to fail over time. There was a batch of bad caps that came out of Japan a few years ago. These tend to die a much earlier death than they should, often not lasting a year. There’s nothing you can do short of removing the caps from the board and replacing them with known good caps.
As long as the card keeps working, I’d stay with it. Just be aware that the other caps are more likely to fail, especially if they are from the same manufacturer. If it’s fairly critical that you keep your system running, you may want to just replace the card now while you can do it at your convenience.
On second thought, sometimes when the cap explodes, it doesn’t just spew electrolyte all over the place. Sometimes it will actually blow the metal case off of the cap. The top of the capacitor’s case is scored to prevent this, but I’ve had a couple of caps go bouncing around inside my case like they were playing some sort of pinball game. The real danger is if the metal of the capacitor case shorts out something while it is bouncing all around. This could cause very bad things inside your computer.
Replace the card.
I say figure out what kind of capacitor it was, and go pick one up at Radio Shack or from the EE lab of your nearest university. Use a soldering iron to get the old one out and put the new one in. If it works, you saved it.
If not… junk it and buy a new card! ATI keeps releasing new “enthusiast” cards, and prices on the GeForce 6 series are coming down pretty fast.
Bad caps have been plaguing the electronics industry for a couple years now. The condensed version is a capacitor manufacturer got ahold of either:
Part of a competitor’s formula (a failed attempt at industrial espionage, perhaps)
An intentionally flawed formula (counter-espionage?)
Or just screwed things up.
A lot of the bad caps got into computers. Some manufacturers will stand behind their goods and replace the item, some won’t.
Might be worth Googling up <your affected item> capacitor failure to see if it’s a common problem for that particular thing, and if anything’s being done for it. Also try calling or emailing the support for the thing and tell them you’ve got exploding capacitors.
How big is the capacitor? Is soldering in a new one an option?
You shouldn’t use anything that you know has a bad capacitor; besides storing electrical energy, they can also be used to smooth out power spikes and several other things. The video card could potentially damage your motherboard if you don’t do something about it. Replace the cap if you know how, or just get a new card.
Alas no; the cap that has blown would have been doing a unique job, as there’s no room for redundancy in highly competitive consumer electronics. As your board is still working, I’d say it was a crude decoupling cap on one of the voltage rail inputs. As well as affording some degree of protection from spikes coming down the power supply rails, it also reduces noise from your video card being fed back into the rest of your PC.
If you want to be extra-safe, replace all the electrolytics. If one has blown, I wouldn’t trust the rest if they’re of the same make. If you choose a low-ESR* type rated at 105 degrees Celcius then it’ll outlast the rest of your PC**. Pay careful attention to the working voltage of the cap too - as a rough rule of thumb, make the maximum voltage the cap sees across its terminals about 2/3 of the rated working voltage of the cap.
*Equivalent Series Resistance. A high ESR (i.e. cheap & nasty) electrolytic will generate a small amount of internal heat, and when the electrolyte dries out, the ESR rises, creating more heat, and sometimes this is enough to build up enough vapour pressure to blow the cap. Large electrolytic caps have weakened vents for safety, while smaller 'lytics just blow the can clean off.
**OK, that’s not a very long time admittedly…
Soldering used to be easy in the good 'ol days, when PC boards weren’t as crowded as they are now. You can try to resolder a replacement cap, but it’s going to be very challenging. Solder points on modern electronics are tiny, and you need an extremely steady hand to duplicate the work of the Taiwanese solderbots. Just a wee bit of excess solder will create a bridge across a few traces that could render a card unusable.
If the card is older, and you’re not a gamer that needs something more powerful, a replacement card with equivalent performance won’t be that expensive.
I have worked in the capacitor industry for a lot of years now.
Yes, there was a bout of bad aluminum electrolytic caps being manufactured a couple of years ago. They weren’t made in Japan, but in Taiwan. Someone switched companies, took a recipe with them and only got part of the formula. Industry link
Even if only a couple are bad, having them gone from the board means you need to replace the board.
First thing I would do is contact the board manufacturer, especially if it’s a fairly new board. All of the companies using these parts KNOW that the parts are highly prone to failure. Rather then doing a mass recall, they have chosen to take their chances with having to replace failed boards.
I had this happen to a video card a couple of years ago. I had no receipt, no packaging, nothing. I had never registered the board with them. I wrote an email to the company, and explained that I knew of the industy problem with these parts, that I had no receipt, and that I needed my board replaced. Even without any proof of purchase, they sent me a return authorization, no questions asked.
You can try replacing the caps yourself, but if you’ve had electrolyte leaking onto the board, there could have been additional damage to the board.