I have Just installed my digitizer over the iPad 3 and ops the Ipad is not working since I know every thing is ok there and the ipad was on tried to connect to usb charger and the sound notification was heared , in this case I knew that i need to reset the tablet . so one long press over the home key with the same time pressing the power on key , the Ipad turned of and then when turned on by the on/off key every thing was good .

not working Update: i have just tried that and the screen does not work ,this means i have to order one more lcd scree