Checking Operational Charging; Checking The External Battery Pack - Lenovo ThinkPad X240 Hardware Maintenance Manual

• If the system status indicator (the indicator in the ThinkPad logo or the indicator in the center of the power
button) 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 operational charging" on page 27.
To check the ac power adapter, do the following:
1. Unplug the ac power adapter cable from the computer.
2. Measure the output voltage at the plug of the ac power adapter cable.
3
2
1
Note: Output voltage of pin 2 of the ac power adapter might differ from the one you are servicing.
3. If the voltage is not correct, replace the ac power adapter.
4. If the voltage is acceptable, replace the system board.
Note: Noise from the ac power adapter does not always indicate a defect.

Checking operational charging

To check whether the batteries charge properly during operation, do the following:
1. Discharge the batteries until the remaining battery power is less than 50%.
2. Connect the computer to ac power to charge the batteries. If the battery status icon in the Windows
notification area indicates that the batteries are not charging, remove the batteries and let them return
to room temperature.
3. Reinstall the batteries. If the batteries are still not charging, replace the batteries.
4. Check the battery status icon again. If the same error still exists, replace the system board.

Checking the external battery pack

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 pack or a battery pack designed for another system is installed, the
system will not charge.
Attention: Lenovo has no responsibility for the performance or safety of unauthorized batteries, and
provides no warranties for failures or damage arising out of their use.
The battery status icon in the Windows notification area displays the percentage of battery power remaining.
To check for detailed battery status information, do the following:
• For Windows 7 operating system: Open the Power Manager program and click the Battery tab.
• For Windows 8 operating system:
– Open the Lenovo Settings program and click Power.
– Open the Lenovo Support program and click Battery Health.
(20V)
Pin Voltage (V dc)
1 +20
2 0
3 Ground
.
Chapter 3 General checkout
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