Cannot Connect

Not really sure of the proper location for this post. I will SOMETIMES not be able to connect to a game, it's usually ARAM but sometimes rift as well and it only happens a couple times a day. I'll get through champ select and the game will launch but the screen is just black, after a minute or two it will make the noise it makes when the game finishes loading and then tell me to check my connection. It's been happening for a few weeks now and I can't find a solution.