Apple Computer, MacBook Pro 15-inch Core i7 2.3/2.6/2.7 GHz (i7-3615QM, i7-3720QM, i7-3820QM), Apple Order Number, MC975LL/A, MC976LL/A, MD831LL/A, Model Number, A1398, Model Year, Mid 2012, Part Name, I/O Board, Manufacture Part Number, 820-3071-A, Compatible Apple Order Number, MC975LL/A, MC976LL/A, MD831LL/A, Compatible Model Number, A1398, EMC Number, EMC-2512, EEE Code, DL62, Compatible Apple Computer Family, MacBook Pro-Retina (15-inch, Mid 2012)Order you product here: 661-6535 I/O Board for MacBook Pro 15-inch (Retina) Mid 2012 A1398 MC975LL/A, MC976LL/A, MD831LL/A (820-3071-A), 661-6535
source http://blogs.applepartsellers.com/661-6535-i-o-board-for-macbook-pro-15-inch-retina-mid-2012-a1398-mc975ll-a-mc976ll-a-md831ll-a-820-3071-a.html
