Power System Checkout; Checking The Ac Power Adapter; Checking The Battery And Operational Charging - Lenovo ThinkPad X1 Yoga 20LD Hardware Maintenance Manual

4. When the ThinkPad logo is displayed, repeatedly press and release the F12 key. When the Boot Menu
window opens, release the F12 key.
5. Use the arrow keys to select ATAPI CDx (x: 0, 1, ...) and then press Enter. The diagnostic program will
be launched automatically.
6. Follow the instructions on the screen to use the diagnostic program.

Power system checkout

To verify if a battery and an ac power adapter are functional, do the following:
1. Turn off the computer.
2. Connect the ac power adapter.
3. Turn on the computer. If the computer can be turned on, it means that either the battery or the ac power
adapter is functional.
4. Insert a straightened paper clip into the emergency reset hole to reset the computer. If the computer is
still powered on, it means that the ac power adapter is functional.
5. Turn off the computer.
6. Disconnect the ac power adapter and turn on the computer. If the computer can be turned on, it means
the battery is functional.
If you suspect a power problem, see the appropriate one of the following power supply checkouts:
• "Checking the ac power adapter" on page 28
• "Checking the battery and operational charging" on page 28
• "Checking the coin-cell battery" on page 29

Checking the ac power adapter

You are here because the computer fails only when the ac power adapter is used.
• If the power problem occurs only when the docking station or the port replicator is used, replace the
docking station or the port replicator.
• If the system status indicator does not blink three times when an ac power source is connected, check the
power cord of the ac power adapter for correct continuity and installation.
• If the computer does not charge during operation, go to "Checking the battery and operational charging"
on page 28.
Note: Noise from the ac power adapter does not always indicate a defect.
Checking the USB-C type ac power adapter
To check the USB-C type ac power adapter, do the following:
1. Connect the computer to a power outlet and turn on the computer.
2. Start Lenovo Companion program, and then click Hardware Settings ➙ Power. The ac power adapter
information is displayed.
Ensure that you use the USB-C type ac power adapter that is shipped with the computer to provide enough
power to the computer. Otherwise, a message will be displayed, prompting you that the computer will not be
charged or will be charged slowly.

Checking the battery and operational charging

Checking the battery
This system supports only batteries specially designed for this specific system and manufactured by Lenovo
or an authorized builder. The system does not support unauthorized batteries or batteries designed for other
systems. If an unauthorized battery or a battery designed for another systems is installed, the system will not
charge.
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Hardware Maintenance Manual