Dell Precision 3431 Small Form Factor Service Manual

Installing the power supply unit or PSU

1. Insert the PSU in the chassis and slide it towards the back of the system to secure it [1].
2. Replace the screws to secure the PSU to the rear chassis of the system .
   
3. Connect the power cable to the connector on the system board [1].
4. Route the system power cable through the retention clips [2].
5. Route the CPU power cable through the retention clips [3].
6. Connect the CPU power cable to the connector on the system board [4].
   
7. Install the:
   1. Hard drive and optical drive module
   2. Front bezel
   3. Side cover
8. Follow the procedure in After working inside your computer.