Power System Checkout; Checking The Ac Power Adapter - Lenovo Ideapad E490 Hardware Maintenance Manual

you to test computer memory and internal storage devices, view system information, and check and recover
the internal storage devices. To use the bootable diagnostic programs, you can create a bootable diagnostic
medium on a USB device or CD.
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
28, and check the power sources. If an error code is displayed, go to "Symptom-to-FRU index" on
page 37 for error code descriptions and troubleshooting hints.
3. When the ThinkPad logo 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.

Power system checkout

To verify a power symptom, do the following:
1. Turn off the computer.
2. Remove the built-in battery.
3. Connect the ac power adapter. If the computer can be turned on, it means the ac power adapter is
functional.
4. Turn off the computer.
5. Disconnect the ac power adapter and install the charged built-in battery.
6. Turn on the computer. If the computer can be turned on, it means that the built-in 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 built-in battery and operational charging" on page 29
• "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 built-in battery and operational
charging" on page 29.
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.
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E490 and R490 Hardware Maintenance Manual
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