in regards to the digitizer, make sure the cable is inserted all the way into the FPC connectors and that the little black tabs are pressed down. Also make sure the digi cable is not being pinched between the glass and the aluminum chassis. Since you've already replaced the wifi antenna I'm assuming that you lifted the logic board to plug the wire in. If that is the case just undo all the logic board screws again and lift it away from the battery terminals and that will shut down the ipad. The logic board should lift pretty easily since you've already loosened the adhesive.