LG Optimus Select 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 reboot the phone.
If it still does not work, please contact
the service center.