I HAVE BEEN HTC SAPP300 ALWAYS HANG IN 15 MNT
I HAVE DONE HARD RESET WITH THIS METHOD TRY THIS
HARD RESET SAPP300 aka TMobile MYTouch My Touch
These steps will help someone Wipe and Hard Reset the TMobile My Touch
1) Press and hold the HOME button and the POWER button together.
2) Keep holding HOME and POWER together for at least 25 seconds, even if the "Startup" screen appears.
3) Release the keys when you see a black screen with a warning sign.
4) At the above warning sign screen, press the HOME and POWER buttons again simultaineously...(10 secs).. and then let them go.
5) Use the trackball to scroll to wipe data/factory reset.
6) Press the trackball in on wipe data/factory reset.
7) When the bottom of the screen displays [DATA WIPE COMPLETED].... roll the trackball to [REBOOT SYSTEM NOW].
Press the trackball in on [REBOOT SYSTEM NOW]
Await for the reboot....Full factory reset completed.