Dell Vostro 3360 (Early 2012) - Manual (Page 35)

4. Remove the screws that secure the I/O board to the computer and remove it from the computer.
Installing the I/O Board
1. Connect the speaker cable and the I/O-board cable to the I/O board.
2. Tighten the screws to secure the I/O board to the computer.
3. Install :
a) battery
b) palmrest
c) keyboard
d) access panel
4. Follow the procedures in After Working Inside Your Computer .
35