Toshiba Satellite Pro P100 - Fading Screen.

Hello,

I'm trying to figure out a problem with a Toshiba Satellite Pro P100 Notebook Computer. It keeps fading gradually while I use it. Over the period of 20 to 60 minutes it will fade by two to three bars before I have to use "Fn" + "F7" to brighten it up again. It continues this over and over.

I've tried updating the drivers for the screen and the graphics cards which didn't fix the problem.
I also tried booting up the computer then pressing "F2" while the computer loaded, to access the bios menu so I could change the display from Auto to Both (given they were the only options available) which also didn't work.

I even tried looking for a relevant driver for this computer on Toshiba's website, but they did not list this specific computer under their drivers section or this type of problem at all.

Has anyone experienced similar problems with this particular model and if so, how do I fix it?!