LG US730 - Manual (Page 15)

Getting to know your phone 15
8. When the screen freezes
If the screen freezes or the phone
does not respond when you try to
operate it:
Remove the battery, reinsert it, then
turn the phone on.
OR
Press and hold the Power/Lock Key
for 10 seconds to turn it off.
If it still does not work, please contact
the service center.