After Screen Change Flashes on and off

We changed the screen on a IPad pro the screen was working however the home button was not so we disconnected the screen and re sat / layed the screen and home button.

Now when we try to power the device on it flashes and powers on (you cans see the home screen) but then goes back off to the black screen, the ipad is recognized in itunes, we have also tested the old screen and tested the new screen on a different IPAD pro and we can confirm the screen works.

Thanks in advance