There are several reasons why your dell laptop screen goes black.  If you are receiving power and you see that your Dell notebook is turning on, then you will want to first check to make sure you are not in external video mode.  On most Dell notebooks, if you press FN + F8 you can switch back and forth from external and internal video.  If this does not solve the problem, you will want to check and make sure your LCD cable is not loose.  If you possess the ability to work with notebooks, you will need to remove the LCD panel and look behind the screen.  When LCD cables are loose, they can cause your screen to go black.  Another important factor is the LCD inverter, this board regulates the voltage to your screen and when it goes bad your screen will also go black.  Also check the LCD cable connection going to the motherboard, it may also be loose.  If you feel that both your LCD cable and inverter are properly working, you may have a video card problem.  If have an external video card, it may be defective or just about to go bad.  You can try to run a Dell diagnostic test on it to confirm its defectiveness.  It is important to first begin with the most basic and easiest components to test.  Once you do, you can narrow it down to the actual problem and find a proper solution to fix it.  If your dell laptop screen goes black, don’t automatically think your screen is defective.  This is a sign of either one of the three things mentioned above; the LCD cable, the LCD inverter or your video source i.e. video card whether external or internal.  If your video is internal and you have replaced both your inverter and cable, then you will need to replace the entire motherboard or have the board itself repaired.  If you need assistance in finding a solution for your dell laptop screen going black, email us and we will help you free of charge.