Power System Checkout; Checking The Ac Power Adapter - Lenovo 20X1 Hardware Maintenance Manual

To create a bootable diagnostic medium, do the following:
1. Go to https://www.lenovo.com/diags
2. Click Lenovo Bootable Diagnostics.
3. Follow the instructions on the Web site to create a bootable diagnostic medium on a USB device or CD.
To use the diagnostic medium you have created, do one of the following:
• If you have created the bootable diagnostic medium on a USB device, do the following:
1. Attach the USB device to the computer.
2. Turn on the computer. If the computer cannot be turned on, go to "Power system checkout" on page
26, and check the power sources. If an error code is displayed, go to "Symptom-to-FRU index" on
page 33 for error code descriptions and troubleshooting hints.
3. When the logo screen is displayed, repeatedly press and release the F12 key. When the Boot Menu
window opens, release the F12 key.
4. Use the arrow keys to select USB HDD and then press Enter. The diagnostic program will be
launched automatically.
5. Follow the instructions on the screen to use the diagnostic program.
• If you have created the bootable diagnostic medium on a CD, do the following:
1. Turn on the computer. If the computer cannot be turned on, go to "Power system checkout" on page
26, and check the power sources. If an error code is displayed, go to "Symptom-to-FRU index" on
page 33 for error code descriptions and troubleshooting hints.
2. Connect an external optical drive to the computer, and insert the CD into the optical drive.
3. Restart the computer.
4. When the logo screen 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 or an ac power adapter is functional, do the following:
1. Turn off the computer.
2. Remove the battery pack.
3. Connect the ac power adapter. If the computer can be turned on, it means that the ac power adapter is
functional.
4. Turn off the computer.
5. Disconnect the ac power adapter and install the charged battery pack.
6. Turn on the computer. If the computer can be turned on, it means that the battery pack 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 26
• "Checking the built-in battery and operational charging" on page 27
• "Checking the coin-cell battery" on page 27

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.
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ThinkPad L14 Gen 2 and ThinkPad L15 Gen 2 Hardware Maintenance Manual
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