Tighten the screws in the following order:
All five fan modules – see Install a Fan Module.
All PCIe carriers or filler panels – see Install a PCIe Card Carrier. Verify that you are installing the PCIe cards back in their original slots using the notes that you took when removing the cards from the slots earlier.
Rear I/O module – see Install the Rear I/O Module.
Both processor modules – see Install a Processor Module or Processor Filler Module.
Main module – see Install the Main Module.
Both power supplies – see Install a Power Supply.