My iPad won't turn on, when i connect it to my laptop the apple logo keeps coming up for a few seconds then and it also won't connects to itunes

My iPad ran out of battery, so I put it on charge and left for 20 mins. When I came back it hadn't done anything, every few seconds the apple logo would appear then go away back the the charging sign. I connected it to my laptop and did the same thing and it didn't connect to iTunes or anything. I don't know what to do.. please help!!!