I have this AMD FX8350 Build which is now 5 years old and inside it I have Graphics card which is 7 year old. Until last week Everything was fine but then after 1 or 2 hours of use screen starts flickering and then vigourously gets black flashes. Computer does not freeze though it works fine. Also I replaced DVI to HDMI cable as I thought it might be problem but it still happens. I am using my PC with a LED TV using DVI to HDMI Cable . Please help as I dont know what to do.