I'd check http://esupport.sony.com/US/p/model-home.pl?mdl=VGNAW290&LOC=3&session_id=658000bd00cfea361b125b578d2ab8b6#/howtoTab for suggestions.
Doing the following experiments might help:
1. Boot into the BIOS setup. Does the same thing happen?
2. Boot into your Windows setup disk. Does the same thing happen?
3. Boot into a Linux disc. Does the same thing happen?
Repeat these with an external monitor in stead of only the built-in screen.
If it's the video hardware, that's part of the motherboard on the usual non-gaming laptop. So you can't simply replace it. That means a new laptop.
I have a sony vaio vgn aw 290. When i boot up the screen goes black after 2 minutes and stays black.
Is it the video card and can the card be replaced i really like the computer and would like to keep it.