i have a samsung galaxy tabA smt350 android 5.02 8.0 inch that wont turn on after an attempt to activate knox protection and i was told to reset my tablet by smart switch and i did so and after a second it was stuck on the boot screen !!!!!
http://www.tomsguide.com/forum/id-3054914/long-hard-reboot-samsung-galaxy-tab.html
http://www.tomsguide.com/forum/id-3054914/long-hard-reboot-samsung-galaxy-tab.html
http://www.tomsguide.com/forum/id-3054914/long-hard-reboot-samsung-galaxy-tab.html
