Screw Notices; Hardware Identity - Lenovo ThinkPad X131e Chromebook Hardware Maintenance Manual

Screw notices

Loose screws can cause a reliability problem. In the ThinkPad 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. For the part number of the screw kit, go to
http://www.lenovo.com/serviceparts-lookup.
• It is recommended to use new screws.
• It is 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 driver, refer to the Torque column in the screw information table for each step.
– Ensure 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 that torque screw drivers are calibrated correctly following country specifications.

Hardware identity

A set of valid hardware identities (HWIDs) are provided by Google. Google logs the exact hardware
combination into a Chromebook computer and creates a HWID. The HWID is used to ensure that all parts are
valid during the repair of the Chromebook computer. The HWID is used for the following purposes:
• Auto-update new patches and software for the lifetime of the computer
• Recover the computer to the factory default settings
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Hardware Maintenance Manual