Radeon 9800xt help please

[bwizz]

Any help appreciated , I have a Radoen 9800 XT ultra with 2 missing caps .The types are I think. is SEPC 1200uf 4v "purple"
I have basic soldering / elctronic skills . these caps have a seemingly hand drawn blue line through the identifying numbers so mavbe identifiying as a special type?
Also the mounting of these caps is unfamiliar ie they have a separating base. question is, are the caps available, if not what alternatives can be used and what to be aware of.
I reasonable card that I came across hopefully worth the effort?

[mariushm]

Those are surface mounted polymer capacitors or just regular capacitors in aluminum casing.

Since you're in UK, Farnell would be a good choice for you but I'm not sure about their shipping fee, which may be 10 pounds or something like that.
RS-Components.com , Mouser.com are also good online stores.

Generally, you should keep the uF value the same, but in your case if you have problems finding capacitors rated for 1200uF, I think it would be safe picking 1000uF ones.

The voltage is less important, they chose 4v probably because it's higher than 2.5 or 3.3v or whatever voltage runs through the circuit - if you can't find 4v ones you may go for capacitors rated for 6.3v or 10v or even higher. In this case, you have to pay attention to the size of the square bottom - the new capacitors must have the same area of the bottom.

Here's some suggestions:

1200uF 10v 10mm : http://uk.farnell.com/panasonic/eeef...105/dp/1539518

1000uF 6.3v 8mm : http://uk.farnell.com/panasonic/eeeh...0uf/dp/1973285
1000uF 6.3v 8mm : http://uk.farnell.com/rubycon/6-3tzv...-3v/dp/1281856
1000uF 10v 10mm : http://uk.farnell.com/panasonic/eeef...10v/dp/1244349

The whole selection is here: http://uk.farnell.com/jsp/search/bro...alues%3D202457

Avoid the ones that are only available in US (you don't want to pay extra to get them to you from there) and stick to brands like Nichicon, Rubycon, Panasonic etc

[Uranium-235]

they might not be missing, sometimes they're re-designed, and instead of changing the board schematics, they just leave parts out that aren't part of the redesign

[bwizz]

Hi thanks for pointers . the caps are missing, as the card was left rattling around in a computer case . one cap was found in the bottom with a broken leg ! I have a close up picture of a same card so i can get the positions and oriantation from that . also any idea what the blue lines across the caps would mean. all the caps on the card have it.

The card did boot to the cmos screen . I stopped the boot when I noticed the fan was noisy. So I expect that the card is otherwise ok and worth the effort.
Again thanks for imput
Brian UK

[PCBONEZ]

Pics would help.
Do you mean printed on lines or hand drawn marks?
.

[bwizz]

Sort of blue felt tip thick line acoss each fitted cap, not sure how to add pics !

[Scenic]

Click "go advanced" below the textbox under the thread.
On the new page, there's a button "manage attachments" under the text box. Click that and a little popup will open. Choose the images and click upload. When it's finished, you can close the small popup window. Then just post it as usual

[bwizz]

Card Pic attached , missing caps were at the top left corner

[PCBONEZ]

Those hand made marks don't mean anything.
Just someone [probably at the factory] doing a spot check on caps installation.
.

[bwizz]

What about the mounting of these cap's then they don't seem to be a normal soldered joint , there are small discs betwean the cap and the board , and the cap legs seem to go into small rectangles , ive not seen this sort of retention before?
again thanks for interest/imput

[PCBONEZ]

Not uncommon, they are just SMD.
SMD = "Surface Mounted Device".
[As opposed the "Through Hole".]

Some boards are actually built to take either kind.
On those you will see the [not round] solder pad on the cap side and a hole in the solder pad with a round pad on the flip side of the board. The two pads are connected through the board. Electrically the same.

If yours is SMD only, then you just need SMD caps.
Generally listed separately from the more familiar Radial [Through Hole] caps on sites that sell caps.
Just need to modify your search to find the SMD caps instead.

Some people will 'hokey-in' Radials by bending leads and using the SMD pads.
That works electrically but doesn't give the cap much mechanical support so they are prone to easily being 'knocked off' and when they go they can take the PCB solder pad off with them.
Not a good idea unless finding an SMD that will work is absolutely impossible. [It sometimes is.]

.
.
The ones mariushm linked to in post #2 are SMD.
.
You DO need to look up the ESR of the old caps and make sure you get caps with the same or less ESR.
[Finding the right caps for low ESR applications is not as simple as just uF and Volts. - Just isn't.....]
.
I've attached the data sheet for the SEPC cap you mentioned.
1200uf 4v is not listed for SEPC but large companies can order custom sizes so that's not too unusual.
All the 4v SEPC list ESR as .007 ohms so that's probably what you should look for.
.

[bwizz]

Ok ta , I have never seen this type of cap previously . how do the smd pads retain then , are they glued ?

[PCBONEZ]

The tabs are simply soldered to the pads on the PCB.
.
If you don't have room around the cap to work it can be a little tricky, but not too bad.
.

[bwizz]

Ok thanks great help , I will report back when done !

[bwizz]

Hi again , I have just had another close look at the displaced cap ( very hard to read as there is a blue pained line through ID but seems to read
3 4 1
SVP
4
this the same ?

[PCBONEZ]

Originally Posted by bwizz

Hi again , I have just had another close look at the displaced cap ( very hard to read as there is a blue pained line through ID but seems to read
3 4 1
SVP
4
this the same ?

Nope. Different Series.
.
Your caps is the next to last one.
.

[bwizz]

Hi thanks , that was quick , who is oscon then , will they supply small a small numjber of these, ps sorry, to confuse matters I had forgot the 1200.

F12 4svp1200m?

[PCBONEZ]

Yes that one.
.
Os-Con is a trade mark for Sanyo Solid Polymer caps.
.

[bwizz]

Hi they are a massive company , unlikely to supply me 2 caps.
any alternative small company in UK
will I get the mounting discs with them?

[mariushm]

I already gave you some suggestions in the second post of this thread.

According to the datasheet for SVP, the F12 is 10.3mm by 11 mm :



and on the next page it says:

4SVP1200M 4 1200 12 5440 0.18 960

which means the capacitor has 5440mA ripple and 0.012 ohm ESR.

The first capacitor I linked to in my first post is 1200uF , 10v , 10.3mm by 10.3mm , 0.006 ohm ESR but only 850mA ripple. So they fit almost perfectly and match all specs except the maximum ripple.

Since the voltage is regulated by the power supply and further by the regulating chips on the video card, the 850mA may be enough but I can't promise you that.

If you don't want to risk it, you have this one :

http://uk.farnell.com/nichicon/pcg1a...10v/dp/1580627

Which is only 1000uF but has the same area and does 0.013 ohm , 4800mA ripple.

I would simply get this one, even if the capacity is a bit lower.


If you don't have problems paying 15 pounds to get the package from US, you have an excellent choice:

http://uk.farnell.com/nichicon/pcj0j...-3v/dp/1580635 1200uF , 6.3v , 0.012 ohm esr, 4700mA ripple (this one is closest to your specs)

Maybe get someone from US to order these for you and mail them to you? You'd still pay about 5 pounds in postage though...