Undetermined problems, Overview of the chromebook usb repair shim – Lenovo ThinkPad Yoga 11e Chromebook User Manual
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1. Run the diagnostic test for the system board in loop mode at least 10 times.
2. If no error is detected, do not replace any FRUs.
3. If any error is detected, replace the FRU shown by the FRU code. Rerun the test to verify that no
more errors exist.
Undetermined problems
If the diagnostic tests did not identify the adapter or device that has failed, if wrong devices are installed,
or if the system simply is not operating, follow these procedures to isolate the failing FRU (do not isolate
FRUs that have no defects).
Verify that all attached devices are supported by the computer.
Verify that the power supply being used at the time of the failure is operating correctly. See “Power system
checkout” on page 28.
1. Turn off the computer.
2. Visually check each FRU for damage. Replace any damaged FRU.
3. Remove or disconnect all of the following devices:
a. Non-ThinkPad devices
b. Printer, mouse, and other external devices
c. External diskette drive or optical drive
d. Wireless cards
4. Turn on the computer.
5. Determine whether the problem has been solved.
6. If the problem does not recur, reconnect the removed devices one at a time until you find the failing FRU.
7. If the problem remains, replace the following FRUs one at a time (do not replace a nondefective FRU):
a. System board
b. LCD assembly
Overview of the Chromebook USB repair shim
You can use a Chromebook USB repair shim (hereafter referred to as the repair shim) as the recovery solution
on the Chrome OS operating system.
The repair shim is a bootable device that is required to service the computer. The repair shim is used for
the following purposes:
• Diagnose problems and restore the system to the factory-default settings.
• Refresh the system with the latest firmware and software.
The repair shim is not necessary when a Customer Replaceable Unit (CRU) is replaced. If a non-CRU is
broken, or there is a strong suspicion that a particular non-CRU is defective, it can be replaced directly.
Otherwise, the repair shim must be used to diagnose problems before any non-CRU is replaced.
The following is the list of CRUs for your computer:
1. ac power adapter
2. Power cord
3. Bottom cover
4. Keyboard
For CRU definition, see “Locating FRUs and CRUs” on page 34.
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