Check if the monitor model supports the power saving circuit [DPM Circuit].
Check if the cable used to connect an external deice is the one provided from LG Electronics.
Power saving circuit [DPM circuit]
In standby [Stand-by / Suspend Mode], if either of horizontal sync or vertical sync signals is not inputted, it is turned off and the power consumption drops below 15W.
In OFF status[OFF Mode], if neither of horizontal sync or vertical sync signals is inputted, then it is turned off and the power consumption drops below 5W.
Try this
Cable is the cause
When the model supports DPM, if the function does not operate, then generally, you are probably using a non authentic cable which is not provided from LG Electronics.
For instance, if specific pins of the HDMI cable fail to detect DPM operation, the function is not implemented and so on.
You are recommended to make a connection with the cable provided from LG Electronics.
In case of monitor with a built-in TV tuner, edit the name of connected device.
On the input terminal connected to the PC, set [HDMI1 or HDMI2] : [Edit Name of Connected Device] to PC.
If you connect the monitor and the PC with HDMI, the screen size or the image quality is not suitable for the PC environment.
When you connect the HDMI cable for the first time, if it says [Is the current input device connected to the PC?] then use a remote controller or the menu button to select [Yes] and check it accordingly.
This guide was created for all models, so the images or content may be different from your product.