Ok, firstly I would like to appologise for wasting your time KiwiJochen.
Turns out when I had added the tv in motion cable i didn't seat the blue cable back into the tv unit properly.

It was really bugging me that both units weren't working which made me look back at what I had changed. I then noticed the blue cable was ever so slightly higher than the white one next to it.
With a little tap it fell into place and voila the screen came alive!