I have noticed the LCD A4 (earlier G5s) and TT (isight 17" model) wont swap out, apparently.

Soo, im thinking about swapping the cable with it.

I had a similar issue with an ibook G3 and ibook G4. I took the G3 screen and put it in the G4, wouldnt work. no video. So i swapped the cables as well, bingo....