Alright how can you tell if your video card is going bad?

i'm not sure if its my TV or if its my on board graphics but their are annoying lines going up my screen. not i'm pretty sure its not my TV because it works just fine with my xbox and Television. ha ha its kind of funny tho if it is because i'm so close to buying a new video card...|||It's either the video card or the VGA cable that you use. I'd recommend changing the cable to a DVI cable first. If that doesn't work, the best bang for your buck right now is the Sapphire Radeon HD 4830 because it's ranked as more powerful than the GeForce 9800 GTX but far less expensive.