If Your Computer Turns On, but the Screen Remains Black
Troubleshooting video and display problems isn't particularly difficult, but it takes time and there are many steps. We'll start with the basics then work our way up from there.
1. Make sure your display (moniter, CRT, LCD, screen, whatever you prefer to call it) is plugged into a wall outlet or power strip and powered on. Also ensure that it is securely plugged into the back or bottom of your display. Many displays do not have removable power cords, making them more prone to shorts and other damage. Check your cable to make sure it isn't damaged.
2. Make sure the power strip or wall outlet that your display is plugged into are functioning by plugging another electrical device, such as a lamp, into it and switching it on.
3. Check the connection between your computer and your display. Make sure that it is completely plugged into both as well as fastened with the attached screws.
5. To double-check any possible cable problems, if at all possible, swap out the screen's power cord and the cable connecting your computer to your display.
6. Swapping out your display is also a good way of narrowing down the problem. If you get the same result with a different display, then you can be near positive the problem is something in your computer. If switching displays fixes it, then the culprit is a faulty display.
7. Try turning your display on and off. Does the power indicator light change? Green means On, amber means Standby, and no light means no power. If your display starts out green when it is turned on, then goes to amber, that usually means that it is not receiving any signal from your computer and therefore assumes it is not needed. The problem is most likely not with the moniter but in the computer.