Why is my I pad secren not working

Do you mean that nothing is displaying on the screen or that it is not responding to Touch commands?

• NO DISPLAY - Depending on the history of the device (drops, water, repairs), you may have either physically damaged the LCD or the backlight driver circuit may be blown. Plug in your device and then shine a bright flashlight on the screen. If you can see a bright image, then it is a backlight issue. If you can see nothing, then it may be a bad LCD.
• NO TOUCH - If the touchscreen does not respond, you will have to replace the digitizer. You can get one here and follow this guide.

Of course, if you give us more details on your problem and what happened before it occurred, we will be able to give you a better guidance.