9800 Pro Broken Cap

[stefmeister]

Hi, I recently brought a Radeon 9800 Pro from Ebay. I brought it knowing that it was damaged. The guy who owned it before me said he had broken off a cap while removing it from his case.

Now having looked at the card i think fixing it should be reletively easy however i need to know what to replace it with. The missing cap is the same as the one which is next to it & that one has the following written on it (470 jFK 3Q7).

Like i said if i could find out what i need to buy i don't think it should be too difficult to fix.

Here is a picture of the part of the card:

[Topcat]

Re: 9800 Pro Broken Cap

You need a 470uF electrolytic cap. A 6.3v will likely be just fine, but in an 8mm can such as that, most you'll find will be 16v, which is fine also. It looks like the PCB is also drilled as well as having the solder pads, so just clear out the holes and use a low-ESR electrolytic. It'll work fine if thats all that's wrong with the card.

[kc8adu]

Re: 9800 Pro Broken Cap

its likely a 470@4v solid polymer cap.good chance the card will work fine after replacement.
its jobs like this that keep me heatgunning the polymers off of otherwise scrap mobo's.
a leaded part will also work just wont look original.
edit.
this is a panasonic type fk and iirc j=6.3v
lack of vent threw me at first.

[willawake]

Re: 9800 Pro Broken Cap





it is a panasonic FK chip type surface mount cap
470uf
the j indicates 6.3v, the FK indicates the FK series
the 3Q7 we ignore, it is the lot number only

[kc8adu]

Re: 9800 Pro Broken Cap

dammit ya got me mid edit:-)

[willawake]

Re: 9800 Pro Broken Cap

lol i had it almost ready a while ago....if people would stop calling on the goddamn mobile i wouldnt be so slow

[Topcat]

Re: 9800 Pro Broken Cap

You guys are too kind...nice info!! I'd have stuck a radial low-ESR lytic in there and called it good

[stefmeister]

Re: 9800 Pro Broken Cap

Many, many thanks for all the help. Does anyone know a place in the UK where i could find a replacement?

Maybe a place Online also.

[Topcat]

Re: 9800 Pro Broken Cap

There ya go:
https://www.badcaps.net/forum/showthread.php?t=613

[willawake]

Re: 9800 Pro Broken Cap

can you confirm that the position indeed has thru holes. you will see two on the back of the card at the same position if it does. show a pic if possible

[stefmeister]

Re: 9800 Pro Broken Cap

can you confirm that the position indeed has thru holes. you will see two on the back of the card at the same position if it does. show a pic if possible

There are holes on the back but from the look of them i don't think the original cap had anything going through them. Directly under where is where i have marked with a green arrow on the pic below.

From what i can tell the original cap was just fixed to the top of the card not going through the cars like a lot of the others on the card.

[arneson]

Re: 9800 Pro Broken Cap

Cleaning up those pads and soldering in a new cap with a fine tip looks very straightforward.
Nice if you can find that cap, if not sub.

[willawake]

Re: 9800 Pro Broken Cap

it is quite busy on the rear of the card. i do not see thru-holes there so you may not use a radial capacitor unless you do a ghetto hack and just solder the leads on to the front of the pcb only.

so if we consider the old cap which is a 6.3v 470uf Panasonic FK, looking at the specs it has a diameter of 8mm, impedance of 0.16 ohm, ripple of 600mA and endurance of 2000h.

in order to replace the cap correctly we should equal or exceed the above specifications and we want an 8mm cap or smaller.

since you are in the UK i have looked at RS and Farnell but whilst RS has the FK caps they do not have the correct values. Farnell is similarly crappy although they do have the sanyo oscon svp 470uf 6.3v at the expensive price of pounds 1.91, Order Code: 4310366. that SVP cap has 0.015ohm esr and 4210 ripple so is greatly superior and really overkill for replacement. but i have seen them used on many graphics cards

while the cap is 8mm like the FK, the case size is E12, whilst the FK has case size F? can anybody explain this please, cos i am not so hot on smt components.

so if we look at ELFA they have the sanyo CV-KX at 1000uf 6.3v with 600 ripple and 0.15ohm esr, case size 8x10.2 at 0.70 euro ex vat. practically identical specs to the FK, just a little less esr.

i will check the case dimensions later to see if it would be ok.

problem is that if you order say 2 caps you will probably fall afoul of the minimum order quantities and shipping when divided per cap will be high. better to order caps for a few projects at once.

are these smt chip type caps easy to rework using only an iron? i see they have little tabs sticking out that it would be possible to solder to? anybody do that kind of repair before?

[stefmeister]

Re: 9800 Pro Broken Cap

I have a Maplins store not too far away frommy house, a mate of mine brought a cap from here for a Geforce4 we repaired a while back, is there anything there that woudl work?

http://www.maplin.co.uk/family.aspx?...ldid=3&doy=1m7

[willawake]

Re: 9800 Pro Broken Cap

no

[gonzo0815]

Re: 9800 Pro Broken Cap

Soldering elektrolytic smt caps is fairly easy. I have done it on a Motorla GP900 radio unit on board charger, wich has blown a 22uf smt cap during operation (the whole car smelled like ).
As long as there is enough space to reach the soldering pad with the solder tip this isn`t any harder than through hole soldering.

[stewart710]

Re: 9800 Pro Broken Cap

I've been reading posts here for a while (but I don't think I've posted before), keep up the good work there is a lot of valuable information here. I have similar situation. One of the caps on my 9800 pro card broke off and I've rigged it so it works, but it looks pretty ghetto. The pins were too short to solder back onto the pads so I had to use some wire and extend them.

What I would really like to do is replace the cap, but I'm having difficulty finding the part:

a34r
470
6.3v

I guess it is a surface mount cap, I was trying to order one through Newark, but I don't want to get the wrong one. if anyone could tell me what part # to order from them, that would help me out a lot. It is very similar to the one in Willawake's picture, but mine has a blue stripe on one side, not black. Mine also has only pads, not holes. Thanks in advance.