screen with out light

KAD, it sounds to me like your backlight is non-functioning. First, of course, try to restart your phone. Press and hold the Sleep/Wake button for a few seconds until the red "slide to power off" slider appears, and then slide the slider. Press and hold the Sleep/Wake button until the Apple logo appears. If that does not work, try to reset your iPhone. Press and hold the Sleep/Wake button and the Home button together for at least ten seconds, until the Apple logo appears. If that does not work, it may be time to open up the iPhone and take a look at the connectors,making sure they are all properly seated and that none of them are broken or torn. If there is no obvious damage, it may just be time to replace the display assembly. If a new LCD does not fix this, then you will have to resort to checking the backlight coil and possibly the backlight IC on the board. Hope this helps, good luck.