Lenovo 81T9, Hardware Maintenance Manual

Page: 31 / 58

Table 3. Factory test items (continued)
FATP Test The FATP Test is designed to test the individual
component to verify its function, such as the display,
audio, camera, keyboard, and other components. It is
recommended that you run all the FATP Test items. Some
test items might require an HDMI monitor or an SD card. If
the devices are not available, the tests can be bypassed,
but with the overall test marked as failed. This will require
the finalized step of the GoogleRequiredTests to be
forced in order to complete the servicing of the computer.
GoogleRequiredTests GoogleRequiredTests checks the system status and
helps reset the system back to the factory-default
settings. If any tests fails, the system cannot be finalized.
Common issues leading to GoogleRequiredTests fail
Issue Description
HWID mismatch
Each Chromebook has a known hardware
configuration. Each configuration is assigned an
HWID. HWID mismatch can be caused by using
unauthorized parts, or missing parts.
If the write-protect function is not turned off before
recovering the computer with the repair shim, it will
also cause HWID mismatch.
Write-protect function is off System cannot be finalized until the write-protect
function is turned back on.
Hardware identify
A set of valid hardware identities (HWIDs) are provided by Google. Google logs the exact hardware
combination into a Chromebook and creates a 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.
Chapter 3
.
Create and use a USB repair shim
25