Dell Precision Tower 3420 Owner's Manual

Installing the power supply unit (PSU)

1. Slide the PSU toward the back of the computer until it clicks into place.
2. Tighten the screws to secure the PSU to the computer.
3. Route the PSU cables through the retention clips.
4. Connect the PSU cables to their connectors on the system board.
5. Install the:
   1. heat sink fan cover
   2. optical drive
   3. hard drive
   4. front bezel
   5. cover
6. Follow the procedure in After Working Inside Your Computer.