When pressing X and C keys it fixed the white display.... and then the laptop crashes playing games...
I was thinking that maybe you had a loose video cable under the keyboard and by pressing down on the keyboard which places down pressure on the keyboard interface it was causing some pressure to a partially seated or intermittent connected video cable to the main board of the laptop and that may be why your white screen corrects itself.
As far as laptop crashing while only playing games. I'd check on CPU and GPU temps when playing games. If either CPU or GPU is going above 60C then you will need to either add a cooler pad below the laptop that helps with better air flow to cool it or you may have to open it up and replace a dried up heat pad or replace a heat pipe that is non functional due to a leak in the pipe.
Speedfan is a good tool to check temps. You can start it and check the check boxes for GPU and CPU Core and have it start to log the graph mode on the one tab. Then with it running start up a game and if the game normally plays say 10 minutes or longer before crashing then hit your windows key at around 5 minutes into the game and look at the speedfan graph and look to see where your temps climbed to while gaming. The temps should start to drop quickly after hitting the windows key because the CPU and GPU will be less loaded down not having to handle the game graphics and so they will cool some from before the windows key was pressed.
www.almico.com/speedfan450.exe
