Can someone tell me what this could be and how to fix it?
See picture, this is what the screen does.
What could this be?
How can I fix this?
Hard Reset didn't worked.
First try to do a Hard Reboot if it Power up the same so
Its Screen Broken , The LCD not the Touch one ! you have to change the LCD
I have seen this before. The LCD is faulty. And since you cant replace the LCD flex cable of the iPad 3 and iPad 4 you'll need to order a new LCD.
You can test it with another LCD, to make sure thats the problem, but as I said, seen it before, so ...
(iff you're Dutch, send me a PM, I have a few LCD's in stock from broken iPad's 3 and 4)