I am glad that the monitor is displaying the optimal resolution. For the monitor not going to sleep, try these steps:
Try the following steps to check if there are any devices or software applications that hinder the monitor from going to sleep mode. Open command prompt: click on start – type 'cmd' – select the result on the top in search results >> right-click and select 'Run as Administrator'.
Type : powercfg -devicequery wake_armed
This command gave a list of devices which prevent the computer from going to sleep mode .For e.g. an Inspiron N5110 could show these 2 devices among the others: Dell Touchpad, Realtek PCIe FE Family Controller.
Here is an example for a desktop computer:
After this is verified, go to the relevant entries in the Device Manager and disable the Power Management options:
Open Device Manager: Click on Start>> type 'devmgmt.msc' in the search box and press Enter.
Search for the respective device. In the above mentioned case, the entries would be under the following categories:
Mice and other pointing devices: Dell Touchpad
Network Adapters: Realtek PCIe FE Family Controller.
Another useful command is powercfg –requests which gives you the list of applications that could be preventing the computer from going into sleep.
If any applications are listed, you may close them if they are on the screen, or you may open task manager and ‘end-task’ the respective process.
How to end-task a process using Task Manager