Replying to Xbox 360 Help

Every once in a while it doesn't read my disc. Doesn't matter what game it is, but it just says "open tray" when there is clearly a disc in there. I open it and close it and nothing happens, i put different games in and nothing happens, and then i turn it off and on and nothing happens. Then after a while it just works. It's not a huge deal because it does work after a while, but it is very inconvenient. Does anyone have this problem and is there a way to fix it without fucking up my xbox?