capacitors

by **markjaycups** » Tue Jun 22, 2004 9:28 pm

this question is for anyone who knows about capacitors...

my old video card (geforce3 ti 200) started to randomly shut off when i would try to play games(anything that required hardware acceleration). i first thought my drivers had gone bad, so i got the most recent ones from nividia, and that didn't fix it. then, a few weeks later, it started to randomly shut off at any time. since summer was starting, i thought maybe it was due to the heat increase in my dorm room. so, i took off the side panel and put a big window fan up to the PC. this worked for a couple weeks, then it started to die anyway. then one night i had the computer going for about 5 minutes before it died, and as soon as it died, i felt around on the card for hotspots and burned myself on 2 capacitors at the rear of the card. i removed the card, and upon closer inspection, the tops of the capacitors had ballooned out.

does anyone know what happened to cause the capacitors to expand and overheat, and then die?

by **commander45** » Tue Jun 22, 2004 10:59 pm

The capacitors can be damaged by an increase in amps flowing through them or by a potential difference (voltage) that is higher than the max voltage, which should be indicated on the capacitor itself. So it could be a power fluctuation in the card that killed your capacitors.

Another way to destroy capacitors is to heat them until the two conductors inside the capacitors meld and touch ...

by **DUMPY** » Tue Jun 29, 2004 7:44 pm

so this pretty much means, even if you replace them, the rest of the card is probably ruined because once the caps die, it can burn out diffenent parts of the board

by **_Taz_** » Wed Jun 30, 2004 1:27 pm

yes and no,

whatever cause the caps to blow may have passed (voltage spike or something) and you replace them and it works, or it could be that it took other things out with it and it's not obvious like a blown cap (burnt diode, fired chip etc..) or it could be that what caused them to blow is still there and will cause them to blow again. without some electronics toubleshooting it will mosdt likely be trial and error. I would suggest if you have a cheap video card to install it in your system and see that it is stable before slapping in a new expensive one.

by **markjaycups** » Wed Jun 30, 2004 4:59 pm

i think the card was just getting old....i bought a geforceFX 5700 ultra to replace the fried card, and i've had it running almost constantly for a month now. the temp on the card has never been above 43 degrees celsius, even after running 2 different benchmark programs several times and then playing splinter cell for a while.

by **Cyrix_2k** » Wed Jun 30, 2004 5:56 pm

You do know that it's very easy to replace caps right? Infact, quite a few cards (and mobos) need to have their caps replaced. Simply find caps that are the same uF/pF value and same or higher voltage rating as the ones on your card and replace the bad caps with new ones. It takes very little skill with a soldering iron to do this.

by **marathonman** » Thu Jul 01, 2004 1:44 am

- if you've never done any soldering before it's worth buying a bit of veroboard and some cheap components and practising. You want to be able to confidently bring the iron to the board, apply the solder, get a good wet joint, and move the iron away again all in one swift movement. It's dead easy once you get the hang of it, but if you're not experienced or a bit rusty, you can very, very easily ruin the card by hanging around 'puddling' the solder with the iron. You want to keep to an absolute minimum, the amount of heat that's actually transferred to the card. The heat should be briefly applied and tightly 'focussed' on the joint to be made.

If the capacitor's legs are near to any semiconductors on the card, it's worth attaching a heatsink to the semi's legs before soldering. Can be tricky these days with the legs no longer being legs at all, really.. a block of copper that sits squarely on the pins of any adjacent chip / transistor / diode might help.

Earth yourself on an all-metal cold water tap or something before starting work, walking across a carpet can charge you up to an astronomical voltage without you realising.. then when you touch a microelectronic device, zap.. I understand they're tougher than they used to be but still, pays to be careful.

by **sanipass** » Sun Jul 04, 2004 2:59 am

ive read a article somewhere about bad capasitors the company whitch makes them got a sweet deal on the gook within them so now there r many hardware out there with these bad caps its sorta hardto trace which company your caps came from but not imposible and some hardware manufactures were volentarily recalling some hardware not shure which one this is just info ive came across a while back because my gfs mothers comp had bad caps and i contacted ibm about it and they told me to ship it off to them they reambursed her for shipping costs and gave her a new mobo with a fresh install all because the caps used on that mobo was from that cheap company

Technology, Support, and News Forum

capacitors

capacitors

Who is online