Sometimes you'll have an out-of-warranty video card that is basically now a paper-weight.
If you were going to throw it out anyway and you have an oven and common-sense you have a chance of repairing the card by re-flowing the solder.
Obviously as with any guide that involves an oven you might burn your house down or burn your hands or inhale toxic fumes or whatever, please don't do anything that you don't feel comfortable doing.
However if the warnings don't scare you. Continue through the guide.
Please note that the guide has been edited by a few people over the years - some parts are not my original writing
Sometimes a fault can be caused by a bad solder joint on a circuit board. cards such as Graphics cards that are exposed to repeated heat/cool cycles may suffer fractured solder joints leading to intermittent or hard faults.