Sorry for being late here, but just a sidenote: In my own experience a very large percentage of problems does not originate in hardware failure. So buying new hardware (like graphics cards) is almost always unnecessary.
While it can fix a problem (e.g. because you install new drivers for your new hardware), it is most often a waste of money. Unless you were planning to upgrade anyway
Heck, even when a piece of hardware is slightly broken in a way, you can often find a workaround to not affect you ever.