Lenovo B580, Hardware Maintenance Manual

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Chapter 6. FRU replacement notices
This chapter presents notices related to removing and replacing parts. Read this chapter carefully before
replacing any FRU.
Screw notices
Loose screws can cause a reliability problem. In the Lenovo notebook computer, this problem is addressed
with special nylon-coated screws that have the following characteristics:
• They maintain tight connections.
• They do not easily come loose, even with shock or vibration.
• They are harder to tighten.
Do the following when you service this machine:
• Keep the screw kit in your tool bag.
• It is recommended to use new screws.
• It recommended to use each screw only once.
• Use a torque screwdriver if you have one.
Tighten screws as follows:
• Plastic to plastic
Turn an additional 90 degrees after the screw head touches the surface of the plastic part:
• Logic card to plastic
Turn an additional 180 degrees after the screw head touches the surface of the logic card:
• Torque driver
If you have a torque screwdriver, refer to the Torque column in the screw information table for each step.
• Make sure that you use the correct screw. It is recommended to use new screws for replacements. If
you have a torque screwdriver, tighten all screws firmly to the torque specified in the screw information
table for each step.
• Ensure torque screw drivers are calibrated correctly following country specifications.
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