wait, I had this once. this is very common.
first thing you have to do is check the manual for this kind of technical issue, if you don't have the manual paper book than look it up at the Internet, or you can follow this online set of instructions which usually this solves the problem, but unplug it first:
https://youtube.com/watch?v=Q5APPT7Rc8o
after you follow through the video plug it back in and it should work just fine