White Screen takes over my computor

So I recently took my computer to the Geek Squad at my local Best Buy because of a random white screen causing me to reboot my computer. I got it back not too long ago, and it was working great, however I can be on the internet all I want but when I open up league I get the same problem. It doesnt always happen, but when it does I usually have to restart my computor to TRY and fix it (sometimes restarting it doesn't work and I have to just let it sit). I feel like this only happens with league on my computer. Here's what happens, my screen goes all white (before, during, or after a game), however I can still hear the league music in the background, I just cant see anything. I'm just wondering if League has caused this for anyone else. Thank you for your help.