My Ipod Touch Wont Work

Hello, my name is Brianna. I have a 3rd gen. ipod touch. so one day my ipod was dying so i put it on my wall charger. then the screen went black and the apple popped up and it stays that way for aboyut 15 minutes. Then the screen goes black again and repeats that whole process. And it wont turn on or do anything, it just keeps doin the same thing over and over. Does anyone know whats wrong with it or how to fix it?