Dell 23.8" OptiPlex 7410 All-in-One Desktop Computer (Gray) - Manual (Page 100)

Steps
1. Place the power-button and I/O board on the display-assembly base.
2. Align the screw holes on the power-button and I/O board with the screw holes on the display-assembly base.
3. Replace the two screws (M3x5) that secure the power-button and I/O board to the display-assembly base.
4. Connect the power cable (DB-PWR) to the power-button and I/O board and close the latch.
5. Connect the high-speed cable (DB-PWR) to the power-button and I/O board and close the latch.
6. Place the power-button and I/O board shield on the display-assembly base.
7. Align the screw holes on the power-button and I/O board shield with the screw holes on the display-assembly base.
8. Replace the three screws (M3x5) that secure the power-button and I/O board shield to the display-assembly base.
Next steps
1. Install the I/O bracket .
2. Install the bottom cover .
3. Install the I/O cover .
4. Install the system-board shield .
5. Install the back cover .
6. Install the stand .
7. Follow the procedure in After working inside your computer .
100 Removing and installing Field Replaceable Units (FRUs)