If you mean the power supply LED at the bottom of the unit ...

There are the following options in the monitor settings:

Power LED On/Off
In the settings you can determine whether the power LED at the bottom of the unit is to be activated or deactivated and change the
and change the behaviour of the LED.

-- Executed: The power LED lights up when the unit is switched on.
-- Standby: The power LED lights up when the unit is switched off.

You can download an operating manual here: https://www.samsung.com/ch...