Author Topic: bad graphic card  (Read 5043 times)

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Offline christosTopic starter

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bad graphic card
« on: February 02, 2014, 01:45:16 pm »
Hello..i have a graphic card from a computer..when i turn it on the display looks like this (
)
it has 7 capacitors and all of them are bad..can someone tell me if its the capacitors that causes this problem or is it the core?
if the computer is on and i touch the graphic card it changes the lines(these on the photo)..ill buy new caps and see if the problem was by the caps..the pc is from an internet caffee...if you need more info pls tell me

..thx
 

Offline SeanB

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Re: bad graphic card
« Reply #1 on: February 02, 2014, 01:54:12 pm »
Replace the caps and see, otherwise you have dead RAM on the card. My bets are on the caps, use low ESR 105C ones to replace, and good brand ones, not the OHL fakes.
 

Offline christosTopic starter

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Re: bad graphic card
« Reply #2 on: February 02, 2014, 01:57:51 pm »
OHL caps?..first time i heard of them
 

Offline SeanB

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Re: bad graphic card
« Reply #3 on: February 02, 2014, 02:41:57 pm »
OHL - One Hung Low, a generic term for fake parts made in a certain country that ships cheap stuff and fake merchandise all over the planet.
 

Online mariush

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Re: bad graphic card
« Reply #4 on: February 02, 2014, 03:13:36 pm »
The probability this is caused by bad capacitors is minimal. 

It's much more likely this is caused by a bad memory chip or some bga balls under the gpu chip loose not making proper connection between chip and pcb. When you're touching the pcb you're probably flexing the board just a tiny bit, enough to alter the connections slightly.
 

Offline Legit-Design

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Re: bad graphic card
« Reply #5 on: February 02, 2014, 03:33:19 pm »
while you have the capacitors removed you could attempt oven reflow for the memory/core which ever is at fault. Since the capacitors went bad the card must have run really hot, which might have interfered with the bga solders.
 

Offline christosTopic starter

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Re: bad graphic card
« Reply #6 on: February 02, 2014, 05:06:09 pm »
Ill put it in an oven and see what it does.and then put the new caps.thx for the advise
 

Online mariush

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Re: bad graphic card
« Reply #7 on: February 02, 2014, 05:23:15 pm »
Don't just put it in an oven man. There's a certain technique to it, can't just put it in your kitchen oven.

Get a good thermometer that works up to 300c  Remove heatsinks or anything that would suck heat, preheat oven to about 100c, put card in and raise temperature gradually to about 200c (in about 2-3 minutes), then increase heat to about 220c quickly (less than a minute) and then within 1-2 minutes the temperature must go up to 240-250c and back down to about 200c , so that the peak temperature will be about 250-260c for about 20-30s maximum.

See these pdf and the graphs and the notes below:

http://ww1.microchip.com/downloads/en/AppNotes/00233D.pdf  (figure 2 and figure 3)

http://www.digikey.com/Web%20Export/Supplier%20Content/Wurth_732/PDF/wurth-pi-solder-profile-leadfree-reflow.pdf?redirected=1
http://mr-sensor.com/english/pdf/reflow/MR_Reflow_profile.pdf

And DO NOT use an oven you make food in! the card may leave toxic substances in it and you and your family may be poisoned.
« Last Edit: February 02, 2014, 05:25:07 pm by mariush »
 

Offline Fabiusp98

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Re: bad graphic card
« Reply #8 on: February 03, 2014, 12:32:51 pm »
Are you sure it's the graphic card? Try the monitor and the cable with another pc and try the pc with another graphics card. The pc, monitor and graphics card would be nice to have.
 

Offline electrolux

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Re: bad graphic card
« Reply #9 on: February 04, 2014, 11:20:10 am »
The monitor  looks as if it's displaying a microscopic view of a cpu
The funniest thing about this signature is that by the time you realize it doesn't say anything its too late to stop reading it.
 


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