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Capacitors on graphics cards...



 
 
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  #1  
Old August 26th 08, 01:34 PM posted to alt.comp.hardware,alt.comp.periphs.videocards.nvidia
~misfit~[_3_]
external usenet poster
 
Posts: 330
Default Capacitors on graphics cards...

Ok, so I have a couple Leadtek WinFast A280 LE AGP 8x VIVO 128MB GeForce
ti4200's. I bought them for my machine and my girlfriends (back when I had
one) and they cost over NZ$300 each new. They were a significant investment
at the time, costing twice as much as the T'bredB Athlon XP CPUs they ran
with.

My ex's card failed before we split and I put it on the shelf and bought her
a 7600GS to replace it. Mine failed not long afterwards and also went on the
shelf. I couldn't bring myself to throw them away considering what they
cost. Actually, only one is VIVO, the other didn't need to be VIVO and was
~$40 cheaper.

The other day I was having one of my periodic clean-outs and I had a good
look at them. One of them had a capacitor that was lifting off it's plug. I
replaced it and now it'll boot in a machine but periodically the machine
crashes. I'm considering replacing all 7 of the non-solid caps and am
seeking opinions.

Interestingly, it seems that Leadtek must have been going through a rough
patch when these cards were produced. Leadtek enjoy a large market presence
in New Zealand so consequently I have a few of their cards around from over
the years. The oldest is a PCI S3 Trio64V+ with 1MB RAM on-board. The newest
is a 7800GT with 256MB RAM. I also have a Leadtek GeForce 2 MX400, an FX5600
and an FX5700.

Here's the interesting bit. The old (and I mean 15 years old) PCI card has
all solid conductive polymer (CP) capacitors. The GF2 has all ali can (AC)
'wet' caps but was made before the great capacitor swindle at the end of
last millenium and is still going strong in daily usage.

Both of the ti4200's have a mix of CP and AC caps but, interestingly, the
mix varies from one card to the other. (They were bought 4 months apart,
right after the public furore over the bad caps scandal.) Also
interestingly, one of them has two caps replaced by one, bridging from the
+ive of one cap stencil to the -ive of the other. (There are two caps on the
other PCB.)

All three of the later cards I have are fitted with all CP capacitors.

Now, I'm thinking that, with the ti4200's, it might be worth replacing the
AC caps with new ones and hoping that the cards are fixed. Correct me if I'm
wrong but it's unlikely that any other components would have failed causing
the cards to fail. They've always been in well ventilated cases and have
never been overclocked. Am I right? Silicon gates and resistors should still
be fine, chances are, if I replace the AC caps then the cards will work and
become reliable again?

I only ask as I'm not a rich man. Quite the contrary in fact (LOL, you
probably guessed that when I said I didn't throw these ti4200's out ages
ago.) Anyway, it'll cost me ~$20 to replace the caps on one card. About the
same as I'd pay for a working ti4200 on an on-line auction site. However,
it's not just the value of a working ti4200 at stake here, it's also the
huge (for me) original investment I made in the cards, (together they
actually cost more than my car at the time) and the satisfaction I'll get if
I can ressurect them.

They're quite fully-featured cards, with monitoring chips on them that tell
Speedfan on-die temp, a thermistor between GPU and HS temp and fan speed.
They also have a series of three LEDs that tell if they're running in 4x or
8x mode and if there is an AGP slot problem. They've also got some pretty
impressive lumps of aluminium on both sides of the cards and the fans are
still working and not excessively noisy.

So... What do you think? It's not *so* much about the money really, it's
more about keeping them out of a landfill somewhere and also justifying the
outlay in, ummm, 2002 or so. I'd be quite bummed out if i mail-ordered the
caps, fitted them and still had a dead card (or two, the postage on the caps
means it'd be more sensible to buy enough for both...)

Cheers, and TIA for any input.
--
Shaun.

DISCLAIMER: If you find a posting or message from me
offensive, inappropriate, or disruptive, please ignore it.
If you don't know how to ignore a posting, complain to
me and I will be only too happy to demonstrate... ;-)


  #2  
Old August 26th 08, 09:28 PM posted to alt.comp.hardware,alt.comp.periphs.videocards.nvidia
Paul
external usenet poster
 
Posts: 13,364
Default Capacitors on graphics cards...

~misfit~ wrote:


Now, I'm thinking that, with the ti4200's, it might be worth replacing the
AC caps with new ones and hoping that the cards are fixed. Correct me if I'm
wrong but it's unlikely that any other components would have failed causing
the cards to fail. They've always been in well ventilated cases and have
never been overclocked. Am I right? Silicon gates and resistors should still
be fine, chances are, if I replace the AC caps then the cards will work and
become reliable again?


When aluminum electrolytics fail, there can be collateral damage. Sometimes
a MOSFET gets taken out (burns), or a toroid gets cooked. It all depends
on whether you stopped using a product, before the damage is done. For
example, if you noted a little instability, but the card kept running,
then chances are the other components would not be affected. But
if you kept driving the thing until the bitter end (black screen),
then chances are something else got cooked and that is when the
black screen hits.

Switching regulators have various forms of current limiting protection,
but they don't protect against all failure modes. Which is why the damage
gets done.

Finding caps is relatively easy, compared to trying to track down a
MOSFET where the label is burned off. And matching a toroid exactly
would be an exercise in frustration -- for those, you're effectively
redesigning the power circuit again. Real designers, who build such
circuits, always build a prototype first and test it, to make sure
their component selections are centered for the application. (We
had some of those pros at work. I just watched them work :-)
They were part of a division that designs power supplies of
various sorts. The company got rid of them, and some of the
guys work for another power supply company in town.)

So if you're going to do it, it is only worthwhile if just the
capacitors are affected. I would not even plug in those cards
once, right now, to see if the screen still appears, because
plugging them in may kill them. The caps are probably
pools of goo.

Paul
  #3  
Old August 27th 08, 12:23 AM posted to alt.comp.hardware,alt.comp.periphs.videocards.nvidia
kony
external usenet poster
 
Posts: 7,416
Default Capacitors on graphics cards...

On Wed, 27 Aug 2008 00:34:41 +1200, "~misfit~"
wrote:

Ok, so I have a couple Leadtek WinFast A280 LE AGP 8x VIVO 128MB GeForce
ti4200's. I bought them for my machine and my girlfriends (back when I had
one) and they cost over NZ$300 each new. They were a significant investment
at the time, costing twice as much as the T'bredB Athlon XP CPUs they ran
with.

My ex's card failed before we split and I put it on the shelf and bought her
a 7600GS to replace it. Mine failed not long afterwards and also went on the
shelf. I couldn't bring myself to throw them away considering what they
cost. Actually, only one is VIVO, the other didn't need to be VIVO and was
~$40 cheaper.

The other day I was having one of my periodic clean-outs and I had a good
look at them. One of them had a capacitor that was lifting off it's plug. I
replaced it and now it'll boot in a machine but periodically the machine
crashes. I'm considering replacing all 7 of the non-solid caps and am
seeking opinions.


Generally those between the 'fets and the load are the more
likely to fail, I'd replace those first if you have a few
spare capacitors lying around or that you could cannibalize
off of something else like a dead motherboard (though with
known good caps still).



Interestingly, it seems that Leadtek must have been going through a rough
patch when these cards were produced. Leadtek enjoy a large market presence
in New Zealand so consequently I have a few of their cards around from over
the years. The oldest is a PCI S3 Trio64V+ with 1MB RAM on-board. The newest
is a 7800GT with 256MB RAM. I also have a Leadtek GeForce 2 MX400, an FX5600
and an FX5700.

Here's the interesting bit. The old (and I mean 15 years old) PCI card has
all solid conductive polymer (CP) capacitors. The GF2 has all ali can (AC)
'wet' caps but was made before the great capacitor swindle at the end of
last millenium and is still going strong in daily usage.


Are you sure those are solid, conductive polymer capacitors
on the old card? In that era they tended to be mostly
tantalum (small rectangular yellow surface mounted) or small
electrolytics which may or may not have been surface mounted
without any vent slits so they did look like solid polymers
but often had a black stripe instead of colored to quickly
identify which they were.



Both of the ti4200's have a mix of CP and AC caps but, interestingly, the
mix varies from one card to the other. (They were bought 4 months apart,
right after the public furore over the bad caps scandal.) Also
interestingly, one of them has two caps replaced by one, bridging from the
+ive of one cap stencil to the -ive of the other. (There are two caps on the
other PCB.)

All three of the later cards I have are fitted with all CP capacitors.

Now, I'm thinking that, with the ti4200's, it might be worth replacing the
AC caps with new ones and hoping that the cards are fixed. Correct me if I'm
wrong but it's unlikely that any other components would have failed causing
the cards to fail. They've always been in well ventilated cases and have
never been overclocked. Am I right? Silicon gates and resistors should still
be fine, chances are, if I replace the AC caps then the cards will work and
become reliable again?


If the cards were pulled out of the systems the moment they
ceased to stay stable there is a good chance they are ok
besides the capacitors, but it is still possible that other
parts were damaged because without the caps functioning
properly the card starts using more current and with ever
higher ripple, that can cause the regulation to go out of
control.

I would try replacing the caps if it can be done cheaply or
at no expense.



I only ask as I'm not a rich man. Quite the contrary in fact (LOL, you
probably guessed that when I said I didn't throw these ti4200's out ages
ago.) Anyway, it'll cost me ~$20 to replace the caps on one card. About the
same as I'd pay for a working ti4200 on an on-line auction site. However,
it's not just the value of a working ti4200 at stake here, it's also the
huge (for me) original investment I made in the cards, (together they
actually cost more than my car at the time) and the satisfaction I'll get if
I can ressurect them.


Original investment isn't so important. Their value is
more in your satisfaction if they can be fixed but you can't
know until you've tried. $20 seems a bit much unless prices
are a lot higher down there and you have to mail-order them.
I'd see if I had an old motherboard lying around with
something close enough, that'll fit in the available space.




They're quite fully-featured cards, with monitoring chips on them that tell
Speedfan on-die temp, a thermistor between GPU and HS temp and fan speed.
They also have a series of three LEDs that tell if they're running in 4x or
8x mode and if there is an AGP slot problem. They've also got some pretty
impressive lumps of aluminium on both sides of the cards and the fans are
still working and not excessively noisy.

So... What do you think? It's not *so* much about the money really, it's
more about keeping them out of a landfill somewhere and also justifying the
outlay in, ummm, 2002 or so. I'd be quite bummed out if i mail-ordered the
caps, fitted them and still had a dead card (or two, the postage on the caps
means it'd be more sensible to buy enough for both...)

Cheers, and TIA for any input.



I don't think it's worth the time, money, and uncertainty of
success to try it today. If I already had the caps lying
around or that could be cannibalized off a motherboard/etc
in a couple minutes time then I might try it... unless you
really need a couple AGP video cards and would end up
actually spending the $20+ on one if you don't get either of
them to work.
  #4  
Old August 27th 08, 04:23 AM posted to alt.comp.hardware,alt.comp.periphs.videocards.nvidia
~misfit~[_3_]
external usenet poster
 
Posts: 330
Default Capacitors on graphics cards...

Somewhere on teh intarweb "Paul" typed:
~misfit~ wrote:


Now, I'm thinking that, with the ti4200's, it might be worth
replacing the AC caps with new ones and hoping that the cards are
fixed. Correct me if I'm wrong but it's unlikely that any other
components would have failed causing the cards to fail. They've
always been in well ventilated cases and have never been
overclocked. Am I right? Silicon gates and resistors should still be
fine, chances are, if I replace the AC caps then the cards will work
and become reliable again?


When aluminum electrolytics fail, there can be collateral damage.
Sometimes a MOSFET gets taken out (burns), or a toroid gets cooked.
It all depends on whether you stopped using a product, before the
damage is done. For example, if you noted a little instability, but
the card kept running, then chances are the other components would
not be affected. But if you kept driving the thing until the bitter end
(black screen),
then chances are something else got cooked and that is when the
black screen hits.


I pretty much swapped them out when I first noticed instability or in one
case artifacts. I've eyeballed the cards quite closely and can't see any
sings of burnt MOSFETS, ICs or inductors.

Switching regulators have various forms of current limiting
protection, but they don't protect against all failure modes. Which
is why the damage gets done.


Right. I can't see any damage and I've even removed the heatsinks and looked
the the GPUs and RAM ICs. (Re-fitted with new TC.)

Finding caps is relatively easy, compared to trying to track down a
MOSFET where the label is burned off. And matching a toroid exactly
would be an exercise in frustration -- for those, you're effectively
redesigning the power circuit again.


For sure. From what I can see though the rest of the components are fine.
Then again, it was only one cap on one card that showed any signs of failure
so who knows?

Real designers, who build such
circuits, always build a prototype first and test it, to make sure
their component selections are centered for the application. (We
had some of those pros at work. I just watched them work :-)
They were part of a division that designs power supplies of
various sorts. The company got rid of them, and some of the
guys work for another power supply company in town.)

So if you're going to do it, it is only worthwhile if just the
capacitors are affected. I would not even plug in those cards
once, right now, to see if the screen still appears, because
plugging them in may kill them. The caps are probably
pools of goo.


Thanks Paul. I'm still not sure of what to do but appreciate your input.

I've uploaded some pics (mainly of the old PCI card) he

http://s308.photobucket.com/albums/kk349/misfitnz/

Cheers,
--
Shaun.

DISCLAIMER: If you find a posting or message from me
offensive, inappropriate, or disruptive, please ignore it.
If you don't know how to ignore a posting, complain to
me and I will be only too happy to demonstrate... ;-)


  #5  
Old August 27th 08, 05:02 AM posted to alt.comp.hardware,alt.comp.periphs.videocards.nvidia
~misfit~[_3_]
external usenet poster
 
Posts: 330
Default Capacitors on graphics cards...

Somewhere on teh intarweb "kony" typed:
On Wed, 27 Aug 2008 00:34:41 +1200, "~misfit~"
wrote:

Ok, so I have a couple Leadtek WinFast A280 LE AGP 8x VIVO 128MB
GeForce ti4200's. I bought them for my machine and my girlfriends
(back when I had one) and they cost over NZ$300 each new. They were
a significant investment at the time, costing twice as much as the
T'bredB Athlon XP CPUs they ran with.

My ex's card failed before we split and I put it on the shelf and
bought her a 7600GS to replace it. Mine failed not long afterwards
and also went on the shelf. I couldn't bring myself to throw them
away considering what they cost. Actually, only one is VIVO, the
other didn't need to be VIVO and was ~$40 cheaper.

The other day I was having one of my periodic clean-outs and I had a
good look at them. One of them had a capacitor that was lifting off
it's plug. I replaced it and now it'll boot in a machine but
periodically the machine crashes. I'm considering replacing all 7 of
the non-solid caps and am seeking opinions.


Generally those between the 'fets and the load are the more
likely to fail,


I'm not sure which ones they are. I've uploaded some pics, mainly of the PCI
card to see if those things that I think are conductive polymer caps really
are. However, there's a pic of the ti4200's there, can you tell me which
caps are most likely to be the ones? I can only see what looks like one
power MOSFET and it's surrounded by caps.

I'd replace those first if you have a few
spare capacitors lying around or that you could cannibalize
off of something else like a dead motherboard (though with
known good caps still).


I've always been a bit wary of re-using caps as I don't have a multimeter
cpable of testing capcitance and, IME, bad caps are the biggest reason for
failure for most electronics.

There are five 1500uf 6.3V caps on each graphics card and I have a (dead)
Asus mobo with seven Nichicon caps on it of the same value. However, the
caps on the graphics cards are 8mm diameter with 3.5mm lead spacing and the
ones on the mobo are 10mm / 5mm and have very short leads. Maybe I can get
them to fit...

As for the smaller caps, I don't have exact matches in my box of bits
although I can get close (albeit with bigger components) but the caps are of
unknown quality.

Interestingly, it seems that Leadtek must have been going through a
rough patch when these cards were produced. Leadtek enjoy a large
market presence in New Zealand so consequently I have a few of their
cards around from over the years. The oldest is a PCI S3 Trio64V+
with 1MB RAM on-board. The newest is a 7800GT with 256MB RAM. I also
have a Leadtek GeForce 2 MX400, an FX5600 and an FX5700.

Here's the interesting bit. The old (and I mean 15 years old) PCI
card has all solid conductive polymer (CP) capacitors. The GF2 has
all ali can (AC) 'wet' caps but was made before the great capacitor
swindle at the end of last millenium and is still going strong in
daily usage.


Are you sure those are solid, conductive polymer capacitors
on the old card? In that era they tended to be mostly
tantalum (small rectangular yellow surface mounted) or small
electrolytics which may or may not have been surface mounted
without any vent slits so they did look like solid polymers
but often had a black stripe instead of colored to quickly
identify which they were.


I'm not sure, they just look like it. I've uploaded pics he

http://s308.photobucket.com/albums/kk349/misfitnz/

Both of the ti4200's have a mix of CP and AC caps but,
interestingly, the mix varies from one card to the other. (They were
bought 4 months apart, right after the public furore over the bad
caps scandal.) Also interestingly, one of them has two caps replaced
by one, bridging from the +ive of one cap stencil to the -ive of the
other. (There are two caps on the other PCB.)

All three of the later cards I have are fitted with all CP
capacitors.

Now, I'm thinking that, with the ti4200's, it might be worth
replacing the AC caps with new ones and hoping that the cards are
fixed. Correct me if I'm wrong but it's unlikely that any other
components would have failed causing the cards to fail. They've
always been in well ventilated cases and have never been
overclocked. Am I right? Silicon gates and resistors should still be
fine, chances are, if I replace the AC caps then the cards will work
and become reliable again?


If the cards were pulled out of the systems the moment they
ceased to stay stable there is a good chance they are ok
besides the capacitors, but it is still possible that other
parts were damaged because without the caps functioning
properly the card starts using more current and with ever
higher ripple, that can cause the regulation to go out of
control.


Both cards were pulled when they were failing but working and all other
components *appear* to be fine...

I would try replacing the caps if it can be done cheaply or
at no expense.


I could probably do one card using caps I have lying around, salvaged from
other components. However, they're all an unknown quantity.

I only ask as I'm not a rich man. Quite the contrary in fact (LOL,
you probably guessed that when I said I didn't throw these ti4200's
out ages ago.) Anyway, it'll cost me ~$20 to replace the caps on one
card. About the same as I'd pay for a working ti4200 on an on-line
auction site. However, it's not just the value of a working ti4200
at stake here, it's also the huge (for me) original investment I
made in the cards, (together they actually cost more than my car at
the time) and the satisfaction I'll get if I can ressurect them.


Original investment isn't so important. Their value is
more in your satisfaction if they can be fixed but you can't
know until you've tried.


Yes.

$20 seems a bit much unless prices
are a lot higher down there and you have to mail-order them.


Both actually. We're a small country and economies of scale come into it.
Also I have to mail-order or travel a fair distance to a store which may or
may not have the caps I require. :-(

I'd see if I had an old motherboard lying around with
something close enough, that'll fit in the available space.


This might be my best option, try it with one of the graphics cards anyway.

Back when I first started replacing caps on mobos I re-used caps on a board
I really wanted to keep (a Gigabyte 440BX Socket 370, Coppermine-capable
board that had a Promise RAID controller on-board and would run at 133/33MHz
FSB/PCI) but I couldn't get it to run stably. I ended up replacing some caps
with salvaged caps a few times until I destroyed the board. That put me off
re-using salvaged caps.

They're quite fully-featured cards, with monitoring chips on them
that tell Speedfan on-die temp, a thermistor between GPU and HS temp
and fan speed. They also have a series of three LEDs that tell if
they're running in 4x or 8x mode and if there is an AGP slot
problem. They've also got some pretty impressive lumps of aluminium
on both sides of the cards and the fans are still working and not
excessively noisy.

So... What do you think? It's not *so* much about the money really,
it's more about keeping them out of a landfill somewhere and also
justifying the outlay in, ummm, 2002 or so. I'd be quite bummed out
if i mail-ordered the caps, fitted them and still had a dead card
(or two, the postage on the caps means it'd be more sensible to buy
enough for both...)

Cheers, and TIA for any input.


I don't think it's worth the time, money, and uncertainty of
success to try it today. If I already had the caps lying
around or that could be cannibalized off a motherboard/etc
in a couple minutes time then I might try it... unless you
really need a couple AGP video cards and would end up
actually spending the $20+ on one if you don't get either of
them to work.


I don't *need* them per se, although it's always handy to have spares
around. I might tinker with one in a day or two using salvaged caps and see
how it goes.

Thanks for the input mate,
--
Shaun.

DISCLAIMER: If you find a posting or message from me
offensive, inappropriate, or disruptive, please ignore it.
If you don't know how to ignore a posting, complain to
me and I will be only too happy to demonstrate... ;-)


  #6  
Old August 27th 08, 05:09 AM posted to alt.comp.hardware,alt.comp.periphs.videocards.nvidia
Paul
external usenet poster
 
Posts: 13,364
Default Capacitors on graphics cards...

~misfit~ wrote:


Thanks Paul. I'm still not sure of what to do but appreciate your input.

I've uploaded some pics (mainly of the old PCI card) he

http://s308.photobucket.com/albums/kk349/misfitnz/

Cheers,


Perhaps if you note the part number for the regulator chip
on each of the regulator circuits, you can find more info
on how they're designed. It might give you a better idea of
what the caps are for. Xbitlabs has volt modded a few cards
over the years, and shown schematic snippets.

http://www.xbitlabs.com/articles/vid...gf4ti4400.html

Paul
  #7  
Old August 27th 08, 05:42 AM posted to alt.comp.hardware,alt.comp.periphs.videocards.nvidia
Phil Weldon[_2_]
external usenet poster
 
Posts: 131
Default Capacitors on graphics cards...

'~misfit~' wrote, in part:
I could probably do one card using caps I have lying around, salvaged from
other components. However, they're all an unknown quantity.

_____

Write down the identification letters and numerals on a capacitor. Enter
this as a search string in Google. You will likely get some hits that will
identify the capacitor type, maximum working voltage, and capacitance.

Only the electrolytic high capacitance (200 micro-farad or more) units in a
switching voltage converter/regulator are likely to have gone bad. The
proper replacements must be low ESR (Equivalent Series Resistance) parts.
If the ESR is too high for the purpose an electrolytic capacitor will
overheat, the electrolyte will expand, and the top will pop (or at the least
the internal structure will rupture and the the capacitor will open or
short.)

Phil Weldon

"~misfit~" wrote in message
...
Somewhere on teh intarweb "kony" typed:
On Wed, 27 Aug 2008 00:34:41 +1200, "~misfit~"
wrote:

Ok, so I have a couple Leadtek WinFast A280 LE AGP 8x VIVO 128MB
GeForce ti4200's. I bought them for my machine and my girlfriends
(back when I had one) and they cost over NZ$300 each new. They were
a significant investment at the time, costing twice as much as the
T'bredB Athlon XP CPUs they ran with.

My ex's card failed before we split and I put it on the shelf and
bought her a 7600GS to replace it. Mine failed not long afterwards
and also went on the shelf. I couldn't bring myself to throw them
away considering what they cost. Actually, only one is VIVO, the
other didn't need to be VIVO and was ~$40 cheaper.

The other day I was having one of my periodic clean-outs and I had a
good look at them. One of them had a capacitor that was lifting off
it's plug. I replaced it and now it'll boot in a machine but
periodically the machine crashes. I'm considering replacing all 7 of
the non-solid caps and am seeking opinions.


Generally those between the 'fets and the load are the more
likely to fail,


I'm not sure which ones they are. I've uploaded some pics, mainly of the
PCI card to see if those things that I think are conductive polymer caps
really are. However, there's a pic of the ti4200's there, can you tell me
which caps are most likely to be the ones? I can only see what looks like
one power MOSFET and it's surrounded by caps.

I'd replace those first if you have a few
spare capacitors lying around or that you could cannibalize
off of something else like a dead motherboard (though with
known good caps still).


I've always been a bit wary of re-using caps as I don't have a multimeter
cpable of testing capcitance and, IME, bad caps are the biggest reason for
failure for most electronics.

There are five 1500uf 6.3V caps on each graphics card and I have a (dead)
Asus mobo with seven Nichicon caps on it of the same value. However, the
caps on the graphics cards are 8mm diameter with 3.5mm lead spacing and
the ones on the mobo are 10mm / 5mm and have very short leads. Maybe I can
get them to fit...

As for the smaller caps, I don't have exact matches in my box of bits
although I can get close (albeit with bigger components) but the caps are
of unknown quality.

Interestingly, it seems that Leadtek must have been going through a
rough patch when these cards were produced. Leadtek enjoy a large
market presence in New Zealand so consequently I have a few of their
cards around from over the years. The oldest is a PCI S3 Trio64V+
with 1MB RAM on-board. The newest is a 7800GT with 256MB RAM. I also
have a Leadtek GeForce 2 MX400, an FX5600 and an FX5700.

Here's the interesting bit. The old (and I mean 15 years old) PCI
card has all solid conductive polymer (CP) capacitors. The GF2 has
all ali can (AC) 'wet' caps but was made before the great capacitor
swindle at the end of last millenium and is still going strong in
daily usage.


Are you sure those are solid, conductive polymer capacitors
on the old card? In that era they tended to be mostly
tantalum (small rectangular yellow surface mounted) or small
electrolytics which may or may not have been surface mounted
without any vent slits so they did look like solid polymers
but often had a black stripe instead of colored to quickly
identify which they were.


I'm not sure, they just look like it. I've uploaded pics he

http://s308.photobucket.com/albums/kk349/misfitnz/

Both of the ti4200's have a mix of CP and AC caps but,
interestingly, the mix varies from one card to the other. (They were
bought 4 months apart, right after the public furore over the bad
caps scandal.) Also interestingly, one of them has two caps replaced
by one, bridging from the +ive of one cap stencil to the -ive of the
other. (There are two caps on the other PCB.)

All three of the later cards I have are fitted with all CP
capacitors.

Now, I'm thinking that, with the ti4200's, it might be worth
replacing the AC caps with new ones and hoping that the cards are
fixed. Correct me if I'm wrong but it's unlikely that any other
components would have failed causing the cards to fail. They've
always been in well ventilated cases and have never been
overclocked. Am I right? Silicon gates and resistors should still be
fine, chances are, if I replace the AC caps then the cards will work
and become reliable again?


If the cards were pulled out of the systems the moment they
ceased to stay stable there is a good chance they are ok
besides the capacitors, but it is still possible that other
parts were damaged because without the caps functioning
properly the card starts using more current and with ever
higher ripple, that can cause the regulation to go out of
control.


Both cards were pulled when they were failing but working and all other
components *appear* to be fine...

I would try replacing the caps if it can be done cheaply or
at no expense.


I could probably do one card using caps I have lying around, salvaged from
other components. However, they're all an unknown quantity.

I only ask as I'm not a rich man. Quite the contrary in fact (LOL,
you probably guessed that when I said I didn't throw these ti4200's
out ages ago.) Anyway, it'll cost me ~$20 to replace the caps on one
card. About the same as I'd pay for a working ti4200 on an on-line
auction site. However, it's not just the value of a working ti4200
at stake here, it's also the huge (for me) original investment I
made in the cards, (together they actually cost more than my car at
the time) and the satisfaction I'll get if I can ressurect them.


Original investment isn't so important. Their value is
more in your satisfaction if they can be fixed but you can't
know until you've tried.


Yes.

$20 seems a bit much unless prices
are a lot higher down there and you have to mail-order them.


Both actually. We're a small country and economies of scale come into it.
Also I have to mail-order or travel a fair distance to a store which may
or may not have the caps I require. :-(

I'd see if I had an old motherboard lying around with
something close enough, that'll fit in the available space.


This might be my best option, try it with one of the graphics cards
anyway.

Back when I first started replacing caps on mobos I re-used caps on a
board I really wanted to keep (a Gigabyte 440BX Socket 370,
Coppermine-capable board that had a Promise RAID controller on-board and
would run at 133/33MHz FSB/PCI) but I couldn't get it to run stably. I
ended up replacing some caps with salvaged caps a few times until I
destroyed the board. That put me off re-using salvaged caps.

They're quite fully-featured cards, with monitoring chips on them
that tell Speedfan on-die temp, a thermistor between GPU and HS temp
and fan speed. They also have a series of three LEDs that tell if
they're running in 4x or 8x mode and if there is an AGP slot
problem. They've also got some pretty impressive lumps of aluminium
on both sides of the cards and the fans are still working and not
excessively noisy.

So... What do you think? It's not *so* much about the money really,
it's more about keeping them out of a landfill somewhere and also
justifying the outlay in, ummm, 2002 or so. I'd be quite bummed out
if i mail-ordered the caps, fitted them and still had a dead card
(or two, the postage on the caps means it'd be more sensible to buy
enough for both...)

Cheers, and TIA for any input.


I don't think it's worth the time, money, and uncertainty of
success to try it today. If I already had the caps lying
around or that could be cannibalized off a motherboard/etc
in a couple minutes time then I might try it... unless you
really need a couple AGP video cards and would end up
actually spending the $20+ on one if you don't get either of
them to work.


I don't *need* them per se, although it's always handy to have spares
around. I might tinker with one in a day or two using salvaged caps and
see how it goes.

Thanks for the input mate,
--
Shaun.

DISCLAIMER: If you find a posting or message from me
offensive, inappropriate, or disruptive, please ignore it.
If you don't know how to ignore a posting, complain to
me and I will be only too happy to demonstrate... ;-)


  #8  
Old August 27th 08, 06:57 AM posted to alt.comp.hardware,alt.comp.periphs.videocards.nvidia
~misfit~[_3_]
external usenet poster
 
Posts: 330
Default Capacitors on graphics cards...

Somewhere on teh intarweb "Paul" typed:
~misfit~ wrote:


Thanks Paul. I'm still not sure of what to do but appreciate your
input. I've uploaded some pics (mainly of the old PCI card) he

http://s308.photobucket.com/albums/kk349/misfitnz/

Cheers,


Perhaps if you note the part number for the regulator chip
on each of the regulator circuits, you can find more info
on how they're designed. It might give you a better idea of
what the caps are for.


Ok. My knowledge of electronic components is fairly rudimentary and reall
yconsists of finding repacement components and soldering them in. :-(

Xbitlabs has volt modded a few cards
over the years, and shown schematic snippets.

http://www.xbitlabs.com/articles/vid...gf4ti4400.html


Yeah, those crazy Russians! I often read X-bit Labs site, usually a good
read.

Cheers,
--
Shaun.

DISCLAIMER: If you find a posting or message from me
offensive, inappropriate, or disruptive, please ignore it.
If you don't know how to ignore a posting, complain to
me and I will be only too happy to demonstrate... ;-)


  #9  
Old August 27th 08, 07:30 AM posted to alt.comp.hardware,alt.comp.periphs.videocards.nvidia
~misfit~[_3_]
external usenet poster
 
Posts: 330
Default Capacitors on graphics cards...

Somewhere on teh intarweb "Phil Weldon" typed:
'~misfit~' wrote, in part:
I could probably do one card using caps I have lying around,
salvaged from other components. However, they're all an unknown
quantity.

_____

Write down the identification letters and numerals on a capacitor. Enter
this as a search string in Google. You will likely get some
hits that will identify the capacitor type, maximum working voltage,
and capacitance.
Only the electrolytic high capacitance (200 micro-farad or more)
units in a switching voltage converter/regulator are likely to have
gone bad. The proper replacements must be low ESR (Equivalent Series
Resistance) parts. If the ESR is too high for the purpose an
electrolytic capacitor will overheat, the electrolyte will expand,
and the top will pop (or at the least the internal structure will
rupture and the the capacitor will open or short.)


Thanks Phil. I've done a few capacitor replacements on motherboards and
always get Low ESR parts. I've always thought that there was really only
three other things that I needed to know to match them up (besides size)
being capacitance, voltage and temp rating.

When I said "unknown quantity" above I meant that I don't know if they're
still within spec as they're salvaged components taken from used, usually
non-working circuits. I mean, I know that, if they're Rubycon, Nichicon,
Sanyo or Teapo that they're likely to be fine but other than that I have no
way of testing them

Cheers,
--
Shaun.

DISCLAIMER: If you find a posting or message from me
offensive, inappropriate, or disruptive, please ignore it.
If you don't know how to ignore a posting, complain to
me and I will be only too happy to demonstrate... ;-)


  #10  
Old August 27th 08, 07:50 AM posted to alt.comp.hardware,alt.comp.periphs.videocards.nvidia
kony
external usenet poster
 
Posts: 7,416
Default Capacitors on graphics cards...

On Wed, 27 Aug 2008 18:30:50 +1200, "~misfit~"
wrote:

Somewhere on teh intarweb "Phil Weldon" typed:
'~misfit~' wrote, in part:
I could probably do one card using caps I have lying around,
salvaged from other components. However, they're all an unknown
quantity.

_____

Write down the identification letters and numerals on a capacitor. Enter
this as a search string in Google. You will likely get some
hits that will identify the capacitor type, maximum working voltage,
and capacitance.
Only the electrolytic high capacitance (200 micro-farad or more)
units in a switching voltage converter/regulator are likely to have
gone bad. The proper replacements must be low ESR (Equivalent Series
Resistance) parts. If the ESR is too high for the purpose an
electrolytic capacitor will overheat, the electrolyte will expand,
and the top will pop (or at the least the internal structure will
rupture and the the capacitor will open or short.)


Thanks Phil. I've done a few capacitor replacements on motherboards and
always get Low ESR parts. I've always thought that there was really only
three other things that I needed to know to match them up (besides size)
being capacitance, voltage and temp rating.


True, but those don't necessarily need to match.
On any decent low-ESR cap it will be 105C temp rated or
higher, that's almost automatic.

Voltage, generally you have a tiny penalty going to
significantly higher voltage than needed, but practically
speaking it doesn't matter, rather what size it is would.

Keep in mind that often when an electrolytic is used, they
use a certain uF value not because it needs that, they use
that uF value because a smaller uF value cap has higher ESR
(assuming still within the same family of capacitor). This
can often be seen when a manufacturer has substituted a
solid polymer for an electrolytic or vice-versa, that the
electrolytic is always a higher uF value if they had any
hope of it remaining a functional circuit. So basically,
with a low ESR electrolytic cap that is rated for 16V or
less, you could get away with trying anything small enough
to fit, the larger the better since you wouldn't be able to
get one to fit if it were so large to create excessive
inrush current.

For example if one were a 6V, 2200uF value, you could
probably get away with using a 16V, 1000uF, a 10V 1500uF, or
higher uF per voltage. Depends on the cap, and design since
some caps may be in parallel. As for voltage, if you have
an old board lying around (with an AGP slot of course) put
the card in, turn the system on, and measure the voltage
across the cap leads. Most will be below 6V so 6V caps are
a practial value to use. Some might be at 12V but



When I said "unknown quantity" above I meant that I don't know if they're
still within spec as they're salvaged components taken from used, usually
non-working circuits. I mean, I know that, if they're Rubycon, Nichicon,
Sanyo or Teapo that they're likely to be fine but other than that I have no
way of testing them


Usually caps do vent if they're a failure point in the
circuit. At worst you make your best guess about which
replacements are ok, solder them in, probe their leads for
continuity to be sure there isn't a short (observing
polarity, meter will beep for a moment as the cap charges),
then put in a non-valuable motherboard to test the result.
 




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