My nexus 7 will turn on and then get to my home screen where my password is and then shut off. Then it will do the same cycle again [turn on, turn off, turn on, turn off.] This happens with me even turning it on every time. I it is charged because it says right before it turns off that i have 28%. i am using the ASUS charger and the cord that it came with. I got this tablet about 11 months ago almost a year. Please help me.