Fujitsu PRIMERGY RX4770 M5 Upgrade And Maintenance Manual page 355

System board and components
Removing the defective top system board
– Remove the heat sink with the CPU from the defective top system board,
see "Removing the heat sink" on page 282.
Figure 198: Removing the top system board locking device
▶ Turn the top system board upside down and remove the three screws (1).
▶ Push the locking device in the direction of the arrow (2).
RX4770 M5 Upgrade and Maintenance Manual 355