Hardware Identity; Prerequisite For Replacing A Fru - Lenovo ThinkPad 13 Hardware Maintenance Manual

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.
Notes:
• 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 screwdrivers 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 and creates an HWID. The HWID is used to ensure that all parts are valid
during the repair of the Chromebook. 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
If unauthorized parts are installed, you might not get the correct auto-updates for your computer, or you
might not recover your computer successfully to the factory default settings. For example, if you install a
different model of the wireless LAN card, which is not the required configuration, the HWID will not match.
HWID is checked by using the repair shim. For information about the repair shim, see "Overview of the
Chromebook USB repair shim" on page 21.

Prerequisite for replacing a FRU

Use the repair shim before replacing any non-CRUs. The following is the list of CRUs for your Chromebook:
• Lenovo USB-C 45W AC Adapter
For CRU definition, see "Locating FRUs and CRUs" on page 36.
For information about how to use the repair shim, see "Using the repair shim" on page 23.
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ThinkPad 13 Hardware Maintenance Manual
90 degrees more
(Cross-section)
180 degrees more
(Cross-section)