bad graphic card  - Page 1
Forum section: electronics / beginners

author: christos
author_rank: Regular Contributor
timestamp: February 02, 2014, 01:45:16 pm
content: 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

author: SeanB
author_rank: Super Contributor
timestamp: February 02, 2014, 01:54:12 pm
content: 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.

author: christos
author_rank: Regular Contributor
timestamp: February 02, 2014, 01:57:51 pm
content: OHL caps?..first time i heard of them

author: SeanB
author_rank: Super Contributor
timestamp: February 02, 2014, 02:41:57 pm
content: 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.

author: mariush
author_rank: Super Contributor
timestamp: February 02, 2014, 03:13:36 pm
content: 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.

author: Legit-Design
author_rank: Frequent Contributor
timestamp: February 02, 2014, 03:33:19 pm
content: 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.

author: christos
author_rank: Regular Contributor
timestamp: February 02, 2014, 05:06:09 pm
content: Ill put it in an oven and see what it does.and then put the new caps.thx for the advise

author: mariush
author_rank: Super Contributor
timestamp: February 02, 2014, 05:23:15 pm
content: 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=1http://mr-sensor.com/english/pdf/reflow/MR_Reflow_profile.pdfAnd 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.

author: Fabiusp98
author_rank: Contributor
timestamp: February 03, 2014, 12:32:51 pm
content: 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.

author: electrolux
author_rank: Regular Contributor
timestamp: February 04, 2014, 11:20:10 am
content: The monitor looks as if it's displaying a microscopic view of a cpu