After starting game my monitor goes black

[AdasT]

So after few days me and my friend we where playing dead island. Then suddenly my screen went black but still I can hear sound of the game only. Then that smell came from my desktop like something was burned I don't know what but it seems from power supply because I tested again I turned back on game and waited for few minutes and the smell was coming like from power supply what I have tested now is counter strike 1.6 battlefield bad company 2 it works But like world of warcraft or dead island garrys mod and probably other games don't work
My pc spec are
*OS:Windows Vista Ultimate
*CPU:Intel Core Quad Q6600 2.40Ghz
*GPU:GTX260
*RAM:4GB
*Hard drive:1TB
*Power Suppply:700W
I just don't know what do to

Some people saying that I need to replace new power supply and later on new graphic card

 

[Route44]

What is the make of your power supply? A bad power supply will cause all kinds of issues and if you are not careful will damage other hardware components. Remove said power supply.

 

[AdasT]

This pc it was good and it has been working good from 2009 my power supply OCZ MODXSTREAM-PRO