Toshiba PORTEGE M300 Maintenance Manual page 270

4.16 System board 4 Replacement Procedures
Installing the system board
To install the system board, follow the steps below and refer to figure 4-28.
1. While fitting the DC-IN jack and modem jack into the slot of base assembly, install
the system board from the sound I/F side.
NOTE: After installing the system board to the base assembly, put the microphone cable
into the slot.
4-42 PORTEGE M300 Maintenance Manual (960-504)