to unlock the GD.. as following progress
SPLOCK clear
   -choice "SET TEST MODE"
   -push F10
   -power on the phones and wait 2-3 seconds
   -push F6 after ENTER two times(the phones will see "INIT SIMLOCK PASSED"
USERLOCK clear
   -push F4 go to "LOCK CONDITION"and read the security code if not 0000
   and disable the userlock from phones menu.

U can try to use ALT+F6, ALT+F4, too.

With best regards.