Anyone know what C509 (capacitor) is on a 7900GT?

[davidos]

Anyone know this technical stuff? thanks!

 

[Hail The Brain Slug]

The only way to know is if you plug it in any try it. It won't break anything else if it is broken, but if it's not critical it should work fine.

 

[Navid]

Originally posted by: XabanakFanatik
The only way to know is if you plug it in any try it. It won't break anything else if it is broken.

What is that statement based on?

 

[Navid]

Originally posted by: davidos
Anyone know this technical stuff? thanks!

Do you have the capacitor? Can you post a picture?

 

[davidos]

In this picture... upper left corner, see the white circle in the upper left corner... to the right of that it looks like the letters ICT are printed in a circle... to the right of that is a little brown capacitor with silver ends... small

7900GT pic

 

[fr]

I had a capacitor knocked off an older Radeon card and the card still worked fine.

 

[Dethfrumbelo]

If it's a cap it should have a rating printed on it in Farads (F), 60uF for example.

Anyway, shouldn't this be covered by the warranty? If not, and it's just the leads that are broken, you could try soldering it back on.

 

[Navid]

Originally posted by: davidos
In this picture... upper left corner, see the white circle in the upper left corner... to the right of that it looks like the letters ICT are printed in a circle... to the right of that is a little brown capacitor with silver ends... small

7900GT pic

OK, I see. That is a surface-mount capacitor. There is no marking on that. Do you have the capacitor? If yes, it can be measured. Then, you can buy one (< $1.00) and have it soldered. Do you still have the capacitor?

 

[davidos]

I still have the cap... and there is no marking on it, you are right. It's so small. I wonder what it actually does?

Originally posted by: Navid

Originally posted by: davidos
In this picture... upper left corner, see the white circle in the upper left corner... to the right of that it looks like the letters ICT are printed in a circle... to the right of that is a little brown capacitor with silver ends... small

7900GT pic

OK, I see. That is a surface-mount capacitor. There is no marking on that. Do you have the capacitor? If yes, it can be measured. Then, you can buy one (< $1.00) and have it soldered. Do you still have the capacitor?

 

[Navid]

http://endeavorquest.net:8880/7900GT_VM/index.htm
In the first picture on this link, you can see that the same capacitor has fallen off too!

You can see it in some of the other boards in the other pictures.

It is in the area where the voltage regulators are. So, it is quite likely that it is a decoupling capacitor. But, I cannot be sure. If so, it helps keep the supply voltage clean for the component that is near it.
Can you confirm if one end of it is connected to the ground plane? The ground plane is a large region on the board that goes almost everywhere on the board. It is often electrically connected to the PSU ground (back wires on a Molex connector).

The supply voltage gets to different components on a board through long tracks. These tracks have effective resistance and inductance. At high frequency with different components operating from the same supply voltage track, they can induce noise on such track. Then, an unwanted ripple could develop on the track causing to limit the operating frequency of some of those components. Decoupling caps help reduce this effect.

 

[davidos]

Originally posted by: Navid
http://endeavorquest.net:8880/7900GT_VM/index.htm
In the first picture on this link, you can see that the same capacitor has fallen off too!

You can see it in some of the other boards in the other pictures.

It is in the area where the voltage regulators are. So, it is quite likely that it is a decoupling capacitor. But, I cannot be sure. If so, it helps keep the supply voltage clean for the component that is near it.
Can you confirm if one end of it is connected to the ground plane? The ground plane is a large region on the board that goes almost everywhere on the board. It is often electrically connected to the PSU ground (back wires on a Molex connector).

The supply voltage gets to different components on a board through long tracks. These tracks have effective resistance and inductance. At high frequency with different components operating from the same supply voltage track, they can induce noise on such track. Then, an unwanted ripple could develop on the track causing to limit the operating frequency of some of those components. Decoupling caps help reduce this effect.

thanks for the great reply! Yeah, i see that the first board pic has the same capacitor as mine missing... then the closeups it is back.

Do you think it is worth it to RMA the board? It "appears" that it is working fine (in windows and about 2 minutes of gaming...)

 

[fuzzybabybunny]

Hey, just replying to davidos' PM. Mine cap is also gone, as shown in the picture.

There are no stability problems, however I can't seem to overclock as high as some other people, despite the fact that I've got the card watercooled and have heatsinks on the RAM with airflow. There could be many factors to my not-so-high overclock, but this missing cap may have something to do with it. Then again, it may not.

Whether you want to RMA.... your call whether you want to spend the shipping and downtime.

 

[Navid]

I would communicate this with the manufacturer.
Just send them an online help request from their web site customer support page. Explain that a component seems to be missing on the board. Provide a picture to them if you can. Ask them, if they think it should be a concern or not.

If your card is from a good manufacturer, like eVGA, they will offer to replace it shipping paid. The customer service from eVGA is second to none.

After they reply to you, you will have more information that can help you make your decision.

 

[orangat]

Did the card come without the capacitor or did it come with the cap rattling in the box?

I did a search and found that there have been reports of caps falling off from the 7900gt and causing problems. I'm not sure if its related to the larger issue of 7900 cards being unstable.
http://forums.gideontech.com/index.php?...3b0aac8ff2537eee0d162c4b&topic=33390.0
http://www.short-media.com/forum/showthread.php?t=45030

 

[davidos]

It was in the box... It is on it's way back to PNY for RMA!
Thanks all for the replies!!!

 

[orangat]

In that case, I wouldn't even bother trying to plug it in. It clearly came as defective and should be rma'd.