There is no force left for the Galaxy Tab, but you can apply this method. After that, you need to plug the charger in the galaxy tab. Then you have to hold power button approx 10 seconds. Also, you need to until the reboot. Your screen will change with the charging battery. Get att customer service to know about further steps. 1-833-554-544
New York, Computer, Reset Samsung tablet without using the power button via Att Customer Service 1-833-554-544