Connections

• The first step to make sure your external monitor is working with your laptop is to see if the monitor has power to it. If it does not, reseat the power cord and try again. If this does not work try another power socket. Once the monitor is on, make sure the connections from the monitor are plugged into your laptop properly, reseating any cables as needed. Make sure you have plugged your monitor into the correct video port also. If this fails, try other known good cables between the monitor and your laptop.
  
  

Resolution

• A common mistake made when hooking up an external monitor to a laptop is choosing a monitor that does not support the resolutions available from your laptop. A display is made up of pixels. It is measured by size of the physical monitor itself, and the pixels available in that space. If you choose a monitor that is too large, your computer will not be able to create the graphics needed to fill those pixels. If your monitor's resolution is supported by your computer, try changing the video settings for your particular model to fit the screen's resolution.
  
  

Ports and Graphics Card

• Make sure that the video ports on your computer are working properly by hooking up a known good display to your laptop. If you are getting video with the known good display, the issue lies with the external monitor. Another issue that sometimes arises is that the graphics card, although built to support the resolution of the external monitor, will not produce graphics to it. This is a tough one to catch, especially if the graphics card is providing video to your laptop. If you have a removable graphics card in your laptop, switch it out and see if the new card will generate graphics to your external monitor.