b.  Remove both PCIe riser cages or fillers, the chassis air baffle, and the PCIe expansion tray (see 
“Remove a 4U PCIe riser cage” on page 255, “Remove the chassis air baffle” on page 270, and 
“Remove the 4U PCIe expansion tray” on page 249).
c.  Remove the fan cage assembly (see 
“Remove the fan cage assembly” on page 153).
d.  Remove the system board air baffle (see 
“Remove the system board air baffle” on page 226) or 
the processor and memory expansion tray and the expansion tray air baffle (see 
“Remove the 
processor and memory expansion tray” on page 219
).
a.  Gently pull and disengage every installed power supply unit.
Step 2.  Disconnect the power backplane cable and remove if from the cable clip. 
Figure 84. Disconnecting the power backplane cable
Step 3.  Grasp and lift the power backplane to remove it. 
Chapter 4. Hardware replacement procedures 195