Dell 23.8" OptiPlex 7410 All-in-One Desktop Computer (Gray) - Manual (Page 76)

4. Align the screw holes on the power-supply connecty bracket with the screw holes on the display-assembly base.
5. Replace the two screws (M3x5) that secure the power-supply connector bracket to the display-assembly base.
6. Connect the processor-power cable (ATX CPU) to the system board.
7. Connect the control-signal cable (CTRL) to the system board.
8. Connect the system-board power cable (ATX SYS) to the system board.
Next steps
1. Install the I/O cover .
2. Install the system-board shield .
3. Install the back cover .
4. Install the stand .
5. Follow the procedure in After working inside your computer .
76 Removing and installing Customer Replaceable Units (CRUs)