how do you restore an ipad that wont restore in itunes keeps getting error code 9

My ipad 5th generation started restarting on its own and then would not restart. I tried updating it in itunes and that failed. Itunes recommended restoring it. The restore fails giving an error code 9. To this point it will not restart, update or restore. I have tried two computers in addition to my own and different cables all to no avail. Any recommendations?