Removing the I/O board.............................................. 55Prerequisites........................................................................................... 55Procedure............................................................................................... 55Replacing the I/O board...............................................57Procedure............................................................................................... 57Post-requisites........................................................................................ 57Removing the heat-sink assembly................................58Prerequisites........................................................................................... 58Procedure (discrete graphics card).........................................................58Procedure (integrated graphics card)..................................................... 59Replacing the heat-sink assembly................................ 61Procedure................................................................................................ 61Post-requisites.........................................................................................61Removing the system board........................................ 63Prerequisites........................................................................................... 63Procedure............................................................................................... 64Replacing the system board.........................................68Procedure............................................................................................... 68Post-requisites........................................................................................69Removing the battery-connector board.......................70Prerequisites........................................................................................... 70Procedure............................................................................................... 70Replacing the battery-connector board....................... 72Procedure............................................................................................... 72Post-requisites........................................................................................ 726