LCD screen goes black immediately after turning on

The iPad was brought in because the customer thought the charging port was bad, i plugged it in and it charged up. When you power on the device it comes up to the apple logo and then comes to their home screen, within a few seconds the screen goes black, if you press the home button and power button quickly ( not hard reset ) the screen will light up and then goes right back to black. iPad is still on because when we plug it into the computer it shows it connected. We have already tried the following and still having the same result. has anyone seen this before?

We have tried:

New LCD

New Power switch

New charging port

I don't think it would be a battery issue because the device isn't shutting completely off. every now and then when you press the power button and home button it will do a soft reset.