A model number is needed to determine the unlock procedure, but most likely you will need a remote to unlock most TV's. Below is a common lock procedure.
You will need a remote to unlock the FPA:
1. Press MENU to see the main menu.
2. Press CH+ or CH- to highlight Preferences.
3. Press OK to enter the Preferences submenu.
4. Press CH+ or CH- to highlight FPA (Front Panel) Lock.
5. Press VOL+ or VOL- to turn on or off FPA Lock.
Choose On to disable all the buttons on the front of the TV. FPA Lock On will appear on the TV screen each time you press buttons on the front of the TV. You can still operate the TV with the remote control. You can still use the POWER button on the front of the TV, but only to turn off the TV (not on). Set FPA Lock to Off to cancel this feature so you can use the buttons on the front of the TV again.
6. Press MENU repeatedly to exit the menu or the menu will automatically disappear within a few seconds if no buttons are