At this point I thought looking at the image that I was lifting the speaker away and tore off the thin cable completely unaware. Please read and view the next two instruction stages before doing this one and then come back and ensure you keep the speaker very close to the screen as you do it.

Before you do this - might be worth checking to see that the insulating gasket in the magsafe port is intact. I was about to buy a new board when I noticed that the gasket was broken (I wouldn’t have noticed there was even a gasket unless it was broken).

Turned out for me it was just this insulating gasket in the outside of the port that was stopping it charging and I didn’t even need to open the back. When I found part of it still intact, I guessed partial insulation might be that causing a short. The gasket is made of very thin tape and sure enough when I made a copy and put that in, it charged fine on the new charger I had bought. The old charger is dead (on this and a friend's machine) so I presume it was fried shorting while I repeatedly tried to charge before. P.S. I made the copy by making an inverse template by pressing Blutac into the port and used that as a block to print an outline onto the tape.