I have this problem many times most specially to my costumers, this is what i do(video card is the problem)

steps:

  1. first of all check all hardware and connection to the motherboard if is running properly.

  2. 2nd UN-slot video card adapter clean the agp/pci slot and video card with paint brush take off all dust and cobweb on it,

  3. 3rd get a pencil eraser and the video card, rub the eraser to the gold part of video card do it side by side until its brighten/shine like gold.

  4. 4th slot again the video card to the mother board,check the other parts connection turn it on if all are ready,,

  5. Good-luck!!

pm.. if what the result to you,,, thanks..

rubberman commented: Clear and concise - well put. +12

Its a fault of low quality video card change this one to best quality , problem wil b resolve