Professionals change the cheapest part first, if they can't find the cause.
My guess is that it is the screen.
So here is the problem i encountered with my laptop.
The screen went silver with some gray vertical lines on it. It was on and working and the screen just went silver. I am trying to figure out is it the graphics or the screen that is bad. I connected the laptop to external screen and everything works fine. I unnistalled the drivers and the screen just went completely black. I connected it again on the external screen and everything works. Then i installed the drivers back and the screen went the same silver with gray lines.
How can i tell is it the graphics card or the screen that is bad, how can i test it ?