I have an ipad4 it was working all of a sudden the screen went black?

Try a reset:

Hold the Sleep and Home button down until you see the Apple logo.

You can use article: http://support.apple.com/kb/TS2802 (it references "iPhone", but is the same for any iOS device)

-Toggle the ringer switch to see if the unit vibrates. If it does, it could be that iPhone is getting power, but is not displaying any image.

-Try turning iPhone off and then on again.

-While connected to the iPhone charger, try to reset the iPhone.

-If the low-battery screen appears, charge the iPhone.

Check here for specific iTunes errors: http://support.apple.com/kb/TS3694

Your issue is with Antivirus/Firewall/Security software interfering with iTunes software communicating with Apple's servers.

Frozen or unresponsive iPad

Resolve these most common issues:

• Display remains black or blank

• Touch screen not responding

• Application unexpectedly closes or freezes

http://www.apple.com/support/ipad/assistant/ipad/

iPad Frozen? How to Force Quit an App, Reset or Restart Your iPad

http://ipadacademy.com/2010/11/ipad-frozen-how-to-force-quit-an-app-reset-or-res tart-your-ipad

What to Do When Your iPad Won't Turn On

http://ipad.about.com/od/iPad_Troubleshooting/ss/What-To-Do-When-Your-Ipad-Wo-No t-Turn-On.htm

iOS: Not responding or does not turn on

http://support.apple.com/kb/TS3281

iPad: Basic troubleshooting

http://support.apple.com/kb/TS3274

 Cheers, Tom 😉