Dell T3600

Window8.1

Please see the pics, cos I really don't understand how to answer. 

We need more data to assist;
* To what computer model is the P2214H attached?
* What operating system is installed on the computer?
* What video card/GPU is installed in the computer?
* What video OUT ports are on the video card/GPU?

That clarified it. You are connected to the monitor VGA in port. Not the white DVI in port.
* Turn the monitor on
* Turn the computer on
* On the monitor, press the 3rd from the top Menu button
* The Menu opens
* Go to Input Source
* Check VGA
* Exit the Menu

Hi, Please see the pics, does my connection is right? there are 4 menu button in monitor, I've tried to select all menu, but it still does not show up the window. 

I really wonder why it have happened like this. My monitor and computer was working well but after unpluged the power cables the vga cables and keep it not work for about 3 days. it happened like this.

I never seen this before.

Hi, thank you for your assist and now my problem had solved. I clean up the hold pc. and Now it work.