Know what to troubleshoot
For a more efficient way of determining the real trouble with your monitor (other than unplugged cables), it is sometimes best that you determine the specific problem on hand. This will lead you to better clue as to how to troubleshoot your system.
The following are helpful tips in finding out what kind of monitor problem you have, if your computer or monitor does not start up as usual: 1) Press the ‘ESC’ key 2) Restart the computer 3) If the power light is colored amber instead of green and no image appears on the monitor, turn off both monitor and CPU. Next, unplug the video and monitor cables and lastly, turn on the monitor and the CPU.