Thanks so much Jobah, Just took the screen connector out and can see mine is the 820-1975-A The model number is  MA446FB

I can't upload pictures directly to here but these links show the board http://s21.postimg.org/3pts3xrzr/IMG_3143.jpg http://s27.postimg.org/oqdo3avib/IMG_3144.jpg   Thanks Chris

Hi JOBAH,   I don't know which models the Logical boards came from sadly, Do you know any way of checking from the chips on the board what version of board I have? Many Thanks Chris

Hi All, Just wanted to ask, I have some logical boards, how can I tell which type they are from the chips on the board. I am interested to know if any of them have the Wolfson DAC Chip2. Thanks in advance Chris