Dell Precision 3431 Small Form Factor Service Manual

Removing power supply unit or PSU

1. Follow the procedure in Before working inside your computer.
2. Remove the:
   1. Side cover
   2. Front bezel
   3. Hard drive and optical drive module
3. To release the PSU:
   1. Disconnect the CPU power cable from the connector on the system board [1].
   2. Unroute the power cables from the retention clips on the chassis [2,3].
   3. Disconnect the PSU power cable from the connector on the system board [4].
      
4. To remove the PSU:
   1. Remove the 3 screws that secure the PSU to the system [1].
   2. Press the blue release tab [4] at the rear end of the PSU unit, slide the PSU and lift it away from the system [2].