What is this?

[andyfox1987]

Hi everyone!

I was recently replacing some parts in my computer, and the case panel fell off on my video card. The card had 4 resistors/transistors fall off when this happened. They are beside the PCI-E connector, and I was wondering what they are and their function. The card still works fine, even when overclocked. I was also wondering if it would be dangerous to still use the card with the condition it is in now.

Here is a pic of the parts I'm talking about, I drew a red circle around them.
http://imgur.com/qugyd.jpg

Any information would be appreciated.

Thanks!

 

[herm0016]

i believe they are capacitors, probably some sort of filter or isolation and while not necessary they offer some protection for the card. if you have a steady hand you can pick up the parts and re-solder new caps on.

 

[andyfox1987]

Thanks for the quick reply! Unfortunately, the parts were so small they have seemed to magically disappear. Could I remove a similar part from a old DDR module and solder that back on? Do these parts have certain specs or do they all work the same? Thanks again.

 

[PM650]

Those are AC-coupling capacitors for the PCI-E lanes; the card will not operate without them, unless the mobo somehow reverts it to x8 or x4 operation. The best thing would be to properly remove one of those still there & measure capacitance with a DMM that can do this. However, I did find this (p8):

PCI Express requires AC coupling between transmitter and receiver. The AC coupling capacitors for both differential pair signals must be the same value, same package size, and have symmetric placement. If possible, TX traces should route on the top layer.
The capacitor value must be in the range of 75 nF to 200 nF (100 nF is best). The 0402 package size is preferred, and 0603 is acceptable

 

[andyfox1987]

Thanks for the help PM650. I have been checking out that document you attached, this makes sense. I just checked GPUZ and it tells me that the bus interface is running 2.0 x16 @ x2 2.0, so I'm running at 2x speed. Honestly, I can say I really haven't seen any dramatic drop in performance. My games run as good as they did before. I don't know how this is possible, because it should run like crap or not run at all right? I think this is a good enough excuse to upgrade, even if it isn't running awful. I'm going to try to see if I can look more into what you've told me and try to find that part, I don't see many places that have those types of parts lying around, any hints?

 

[bobsmith1492]

Digi Key:

http://search.digikey.com/scri...ail&name=445-4958-1-ND

 

[andyfox1987]

Thanks bob! You guys have been really helpful. I'm glad there's still somewhere you can go on the internet to find good help and well mannered people. Any tips about how I'm going to solder these little suckers on??

 

[PottedMeat]

Originally posted by: andyfox1987
Thanks bob! You guys have been really helpful. I'm glad there's still somewhere you can go on the internet to find good help and well mannered people. Any tips about how I'm going to solder these little suckers on??

I usually use 2 cheap pencil irons to remove an old part, if not, just use the long edge of the tip. Make sure the solder did not bridge the contacts. If it did, use some solder wick or lay some stranded wire on the connection and put the iron tip on top until the solder wicks away. If you put it on too long the traces may peel off. Use tweezers to align the part and tack the sides on one at a time. There may be enough solder remaining that you won't have to add any.

 

[bobsmith1492]

Sharp tweezers, iron, solder, and eyesight. Everything must be sharp and fine.

ED. More specifically, get some solder braid and use it to remove all solder from both pads. Take some isopropyl alcohol on a Q-tip and wipe the pads clean. Put a tiny dab of solder on one pad. Then, hold the cap with tweezers in one hand and heat that solder dab with the iron in the other hand. Line up cap, remove iron, then release tweezers. Don't hold the heat on for more than a few seconds. With the cap in place, solder on the other side. That's my system.

 

[andyfox1987]

Nice! I think that about does it guys. I appreciate all of your help. You guys saved me a good bit of money. I'm new to this forum and now I know where to go for technical help. Thanks guys! Have a great week.

 

[bipra]

Originally posted by: herm0016
i believe they are capacitors, probably some sort of filter or isolation and while not necessary they offer some protection for the card. if you have a steady hand you can pick up the parts and re-solder new caps on.

With increasing questions about skype, wireless connections on campus and your connections at housing, I have decided to start this thread for current and incoming students with computer-related questions. Before coming to AUA, I worked a half a year as network tech at my university and a year for H&R block as a field software tech.

I have experience with many OS's and I currently dual-boot Vista and Ubuntu (linux). Feel free to ask away and other students join in because I get busy.

 

[bobsmith1492]

Originally posted by: bipra

Originally posted by: herm0016
i believe they are capacitors, probably some sort of filter or isolation and while not necessary they offer some protection for the card. if you have a steady hand you can pick up the parts and re-solder new caps on.

With increasing questions about skype, wireless connections on campus and your connections at housing, I have decided to start this thread for current and incoming students with computer-related questions. Before coming to AUA, I worked a half a year as network tech at my university and a year for H&R block as a field software tech.

I have experience with many OS's and I currently dual-boot Vista and Ubuntu (linux). Feel free to ask away and other students join in because I get busy.

Can I have an Ipod?

 

[SonicIce]

Originally posted by: bipra

Originally posted by: herm0016
i believe they are capacitors, probably some sort of filter or isolation and while not necessary they offer some protection for the card. if you have a steady hand you can pick up the parts and re-solder new caps on.

With increasing questions about skype, wireless connections on campus and your connections at housing, I have decided to start this thread for current and incoming students with computer-related questions. Before coming to AUA, I worked a half a year as network tech at my university and a year for H&R block as a field software tech.

I have experience with many OS's and I currently dual-boot Vista and Ubuntu (linux). Feel free to ask away and other students join in because I get busy.

LOL wtf

 

[Schmide]

Another trick I've used . Glue the resistors in place before soldering. Realize that some glues will melt pretty quick when the heat from the iron is applied.