I have a toshioba quasimo g30-204 laptop - blue vertical lines

i was using my laptop when the screen went black, i had to re-boot. when i did so it would not and still does not load in normal mode, i can only boot up in safe mode and i have blue vertical lines all over my screen. this happened about a year ago and i had to send my laptop off for repair for about 6 weeks, and had a new circuit board installed. what causes this problem and can it be rectified by me.