Video card no issues?

[Crash1hd]

Hello

Can anyone explain how it is that this video card still works? it also doesnt seem to have any issues that I can tell (as you can see one of the caps leads is off the board, well its kinda hard to see but it is)

Would I be safe to assume that all I have to do is re-solder the connection?

Thanks

[mariushm]

Re: Video card no issues?

Those 3 capacitors are probably in parallel so the capacity adds up and the video card sees all three capacitors as a single bigger one.

A possible scenario would be this:

Let's say the total required there was 2200uF - a single capacitor could have been too big to fit in that area (too high) so instead they decided to go with three 820uF ones (chose this because it's a sort of standard value). 820 uF x 3 = 2460 uF

Now these capacitors usually have +/- 20% tolerance, so generally when someone designs a circuit and picks a value like 2200uF knows the capacitor that gets mounted on the card could be anything between about 2000uF and 2400uF.
At the same time, some quality capacitor manufacturers actually make the capacitors with a higher value and label them lower - for example the capacitors on the card could actually be 880uF-900uF (+7-8% better than specified but remember, it's still within +/-20% tolerance for each one).

So in our scenario, these 2 capacitors left could very well have 1700-1800uF, which is close enough to the 2000uF-2400uF range.

The capacitors could also be way over what the minimum required for that card, because manufacturers have to assume people may have very poor quality power supplies. The card could work well in your PC with a decent psu but may not work in another computer with cheap power supply.

Ok... now looking at the picture, it looks to me that those two polymer capacitors on the edge have problems. I would replace all 4 green capacitors, the two green polymer ones and maybe the one with black markings as well, the 1000uF one (but it doesn't look like it needs to be replaced to me).

The four capacitors don't look swollen but without knowing why that capacitor got loose, I'd recommend replacing those - it's a 1-2$ job. The polymers are a bit more expensive, probably 0.7$ each.

[Crash1hd]

Re: Video card no issues?

Thank you very much for the reply and lots of info,

The reason that one is loose is due to laziness on my part of trying to pull out and put in hdd and you are right none of them are bulging.

I have never soldered anything onto anything of any importance lol but there is always a first. I will go to my local electronics supply shop and pick up some caps to replace them.

I also have to pick up a desolder suction tool as I do not have one.

again thank you.

[mariushm]

Re: Video card no issues?

I don't really recommend buying capacitors from stores like Radioshack - they're generally general purpose, not for more sensitive stuff like pc components.

As it works now Ok, don't just hurry and buy generic capacitors, it's better to just order some quality parts from a good online store - generally if you're in US there's digikey.com, if you're in Europe there's farnell.com .. .there's also mouser.com which may ship to you at reasonable prices.

Go for brand names like Nichicon (HN, HM, I think PW series are good enough as well), United Chemi Con, Panasonic (FM,FR,FC series are great), Rubycon (RX series for example) and for capacitors rated for 105c - even though for a video card it may not be needed, it can't hurt and the price difference is not big. You're looking at 0.3-0.5$ a piece, plus a few dollars in shipping, depending where you live.

As for solder sucker - it can't hurt to have in your house but if you don't regularly fix repair things, don't think you should buy one now. The capacitors have very small wires so if you heat up the terminals from the other side and carefully press with your finger on the capacitor they should come out right away.

Then you can just clean the solder from the gun with some flux and heat the solder on the board again and the solder should come off easily.

[Crash1hd]

Re: Video card no issues?

Alright, I am in Canada and we have some really good electronics stores and yeah I dont mean radio shack but I am in no rush to fix it as you said its working. This being said since the motherboard is shot (It looks like I will be upgrading the board for now and then play with the old board later) I picked up a sucker off of eBay for $2 so I couldn't complain. I should look into getting some flux though as I have that copper stuff but I am not sure what flux is

[PCBONEZ]

Re: Video card no issues?

Those 3 capacitors are probably in parallel so the capacity adds up and the video card sees all three capacitors as a single bigger one.

A possible scenario would be this:

Let's say the total required there was 2200uF - a single capacitor could have been too big to fit in that area (too high) so instead they decided to go with three 820uF ones (chose this because it's a sort of standard value). 820 uF x 3 = 2460 uF

Now these capacitors usually have +/- 20% tolerance, so generally when someone designs a circuit and picks a value like 2200uF knows the capacitor that gets mounted on the card could be anything between about 2000uF and 2400uF.
At the same time, some quality capacitor manufacturers actually make the capacitors with a higher value and label them lower - for example the capacitors on the card could actually be 880uF-900uF (+7-8% better than specified but remember, it's still within +/-20% tolerance for each one).

So in our scenario, these 2 capacitors left could very well have 1700-1800uF, which is close enough to the 2000uF-2400uF range.

The capacitors could also be way over what the minimum required for that card, because manufacturers have to assume people may have very poor quality power supplies. The card could work well in your PC with a decent psu but may not work in another computer with cheap power supply.

Ok... now looking at the picture, it looks to me that those two polymer capacitors on the edge have problems. I would replace all 4 green capacitors, the two green polymer ones and maybe the one with black markings as well, the 1000uF one (but it doesn't look like it needs to be replaced to me).

The four capacitors don't look swollen but without knowing why that capacitor got loose, I'd recommend replacing those - it's a 1-2$ job. The polymers are a bit more expensive, probably 0.7$ each.

Another concern, using your 3-cap scenario, is that the Ripple Current for three caps is now going through only two.
That means the two caps are handling 50% more Ripple that they should be and it's likely to be over their max rating for Ripple.
Operating caps with Ripple in excess of their rating will overheat and destroy them.
How long? - Depends mostly on how far over their rating they are at.
.

[Agent24]

Re: Video card no issues?

Ok... now looking at the picture, it looks to me that those two polymer capacitors on the edge have problems. I would replace all 4 green capacitors, the two green polymer ones and maybe the one with black markings as well, the 1000uF one (but it doesn't look like it needs to be replaced to me).

Polymer? What polymer?....

[Uranium-235]

Re: Video card no issues?

yeah those metal jacketed ones aren't polymer, they're polymer wannabies. Usually if it has a vent, its a lytic

[Koda]

Re: Video card no issues?

Sacon!!!!