My Toshiba Laptop has been acting up the last few days. When I start my computer the screen is split into three columns. Column one is working fine, but column 2 and 3 are just solid black and solid white. So only 33% of the screen is working. If I gently tap the screen with my hands a few times, the monitor comes back to normal. So, is this the screen itself or would it be a video card or what could it be? Thanks.