My friend just offered my little brother an iPhone 4s if he could fix it. I downloaded iTunes, and we put it in the usb plugged up to my laptop. When we plug it in, or even turn it on, the charging icon comes and we charge it with the usb, but the apple logo just keeps turning off and on and it seems like it's rebooting itself. I press the homebutton and "Windows could not detect device." Any suggestions?