Dell U3224KBA User Manual page 88

To unlock the button(s).
Press the left directional navigation of Joystick for four seconds until a menu appears
on the screen. The following table describes the options to unlock the front-panel
control buttons.
Options
1
Menu Button unlock
2
Power Button unlock
3
Menu and Power Button
unlock
88 | Operating the monitor
Select Option:
Description
Use this option to unlock OSD menu function.
Use this option to unlock power button to turn off
the monitor.
Use this option to unlock OSD menu and power
button to turn off the monitor.