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Re: [PLUG] OT: SMD capacitor
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63-37 isn't that weak... it has a shear strength of 6200 psi... also,
large scale manufacturers quit using lead-based solder a long time ago
(even long before Europe declared lead was evil)... 96.5/3.0/0.5 has
been the solder of choice for more than a decade for large-scale
manufacturers. What sucks about that for people at home is that it has
an insanely high melting point (219C) instead of the 63/37's more
10W-iron-friendly 183C.
Also, tants come in many different case sizes... Here's a handy chart:
A - 3216-18 (3.2mm x 1.6mm x 1.8mm)
B - 3528-21 (3.5mm x 2.8mm x 2.1mm)
C - 6032-28
D - 7343-31
E - 7343-43
G - 3216
H - 3528-12
P - 2012-15
R - 2012-12
S - 3216-12
T - 3528-12
V - 7361-38
W - 6032-15
Y - 7343-20
What he has on his card looks like a D/E/Y X-Y footprint... so any one
of those three case sizes will work. Since it's a bulk cap, I'd still go
with a lower ESR cap if possible instead of just a general purpose cap..
It just so happens that, rummaging through my desk drawer at work, I
found an AVX TAJ/TPS capacitor kit... in it I have a little baggie of
68uF 16V low ESR (70 mOhm) caps... If the dude with the video card
emails me his address, I'll drop one in the mail today...
E
tom.hornberger@verizon.net wrote:
On Wednesday 12 July 2006 22:47, Eric Hidle wrote:
An electrolytic would be fine, but an SMD would be preferred to a
radial....
Polystyrene caps can run $5-$10.... low ESR caps can be a tad much...
It takes a LOT to break a component off of a board. It doesn't happen
w/o a lot of force..
E
gyoza@comcast.net wrote:
Thanks. That really narrows it down. I see that Mouser has some for
about $2.22 each. (Expensive for caps, isn't it?)
So, I should really avoid a electrolytic cap? I have a 16V, 100uF and
35V, 47uF available. Or should I just return this card to the ebay
seller?
I'm still wondering how a component could be knocked off the board at
both ends *and* one lead become completed broken off the component.
Could a loose heatsink/fan moving about during shipping do that?
Eric Hidle wrote:
Judging from the location, it doesn't look like a DC-DC output cap,
but rather a bulk supply cap for the graphics processor. The DC-DC
converters are nestled in that jungle of tin cans at the up-end of
the board. That said, it could very well be a tantalum... 16VDC is a
pretty high voltage for a solid polymer cap in that large a
capacitance...
Anyway, check out AVX TPS series caps for a replacement... they're
probably available at digikey in onesies... perhaps a TPSD476M016
E
gyoza@comcast.net wrote:
Here are pictures of the capacitor.
http://reddragoncanoeclub.org/paul/9600/
The card is just to show the location and relative size of the cap.
The only difference is that my cap is black and my board is green.
heh.
I was assuming the cap is tantalum.
Eric Hidle wrote:
What package is the bad capacitor in and what chemistry was it?
Chances are it was a low-ESR polystyrene or aluminum-polymer cap,
in which case you do not want to replace it with just any
off-the-shelf tantalum or electrolytic capacitor. The DC-DC
converters on video cards are ultra-clean and depend upon a very
low amount of resistance in the output caps to minimize ripple.
Was this thing a round tin can?
E
gyoza@comcast.net wrote:
Nevermind. heh. I will try the radial capacitor. (I found
#electronics on Freenode.net)
gyoza@comcast.net wrote:
I have a Radeon 9600 Pro video card with a bad surface mount
capacitor (C2). I'm not sure of the value of it. It's labeled
"47" and "16V" which I read as 47uF, 16V. Does that sound
correct? It is a black SMD capacitor with a white end to
indicate polarity. The size is roughly 7mm x 3.5mm x 2mm. I
need to identify it enough to replace it. Would it be too wacky
to use a huge radial capacitor to replace it?
____________________________________________________________________
<snip>
It's probably a Tantalum. The 47uF, 35V will work OK as long as the footprint
is the same. Most of the Tants have the same footprint, just different case
heights (makes board layout easier!) I might have some 47uF, 16V at work,
I'll check tomorrow. The cap coming off doesn't surprise me, 63/37 solder is
very soft and easily deformed. If you need someone to solder it on I have
access to the proper equipment at work.
HTH,
Tom
___________________________________________________________________________
Philadelphia Linux Users Group -- http://www.phillylinux.org
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___________________________________________________________________________
Philadelphia Linux Users Group -- http://www.phillylinux.org
Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce
General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug
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