What part to change if bad display on screen

[sameerk28]

I have Sony Vaio fz21z It was heating a lot since I bought it and after some months wen the warranty was over the laptop started giving problemslike restarting and the screen use to turn black, later it started getting colorful lines on startup the bios menu n then on the main display aswell as if in safe mode with all colorful lines vertical n horizontal, i reinstalled Vista Business and and the display was gre8 as if new, later it automatically restarted and the display was as if in safe mode, from personalize display i tried to change the resolution setting and then the display is completely gone i can hardly make out the words and its all blur n not visible all color distorted so cant read at all, what is the problem with it and what part needs to be changed ?
cant take to the service center as instead of paying their charges I could buy a new one.

 

[wa1]

It could be your motherboard or your gpu...
It's a laptop, it's hard to analyzing what caused the problem.
Yes, as u said before, the price for repairing is usually high and nearly as expensive as the laptop itself...