I’m using a laptop and my external monitor won’t go off power saving mode – how can I do this? I am running Windows 7.
Open the Power troubleshooter
Change, create, or delete a power plan (scheme)
Fix power consumption problems and extend the laptop battery life
Has the monitor worked before?
Try manually turning it off and back on again using the power button or by unplugging power cable. Try reconnecting the cable between the monitor and your laptop.
Right-click on your Desktop and select "Screen resolution". If the monitor is properly detected it should shown as a secondary display. You can then select to duplicate or extend your screen, or to use one display on it's own.
If there is no second display device shown reconnect all the cables between your laptop and the monitor.