IPad doesn't turn on

Hi folks, my IPad 64Gb hasn't been working for a while. I have been trying to turn it on for a whole week. I also tried pressing for 10-15 sec the home and the on/off button, daily, in the morning, in the evening. I have left it charging at a wall outlet, and know I left it charging at my computer. Any suggestions? No "apple" message are displayed, or any light, or whatever!... No sign of intelligent life. Please, help me. Ipad has never fallen down. Thanks in advance for any information.