Lenovo x3530 M4 Installation And Service Manual page 69

Figure 40. Heat sink placement
c. Press firmly on the captive screws and tighten them with a screwdriver. The follow illustration
shows the sequence in tightening the screws, which is also shown on top of the heat sink.
Begin with the screw labeled as "1", then "2", "3" and finally "4". If possible, each screw
should be rotated two full rotations at a time. Repeat until the screws are tight. Do not
overtighten the screws by using excessive force. If you are using a torque wrench, tighten the
screws to 8.5 Newton-meters (Nm) to 13 Nm (6.3 foot-pounds to 9.6 foot-pounds).
Figure 41. Sequence in tightening the screws
Step 10. If you installed the second microprocessor, install the two fans on Fan connector 4 and Fan
connector 6 of the system board respectively (see "Replacing a fan" on page 213).
Step 11. Reinstall the air baffle, (see "Replacing the air baffle" on page 74).
Step 12. Reconnect any cables that you have disconnected from the adapters or system board.
If you have other devices to install or remove, do so now. Otherwise, go to "Completing the installation"
on page 73.
Thermal grease
The thermal grease must be replaced whenever the heat sink has been removed from the top of the
microprocessor and is going to be reused or when debris is found in the grease.
When you are installing the heat sink on the same microprocessor that is was removed from, make sure
that the following requirements are met:
• The thermal grease on the heat sink and microprocessor is not contaminated.
.
Chapter 2 Installing optional devices
55