Hard Reset LG GM200

Press Power button to switch on device.
Open phone's Dialer by tapping Call key, other way is to go on Standby screen.
Type in code using keypad: 1809#*101# or 2945#*101#
Call key to confirm whole Master reset process.
After restart device should work properly now.

WARNING !
Hard Reset will erase all of your data
All described operations you are doing at your own risk.