I have managed to pin point the fault a little further. The issue is that it is not charging when on the dock despite the green light. I have notice that when I apply pressure to the unit downwards toward the dock this gives it a charge. Unfortunately, I can't do this for too long so I'm only getting short bursts of charge.
Has anyone had any experiance with this type of fault and had a solution. (Noticed that the gromet at the rear is missing)