ThinkPad Edge E445, Hardware Maintenance Manual

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• If the power-on indicator does not turn on, 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 31.
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. See the following figure:
Pin Voltage (V dc)
1 +20
2 0
3 Ground
1
2
3
(20V)
Note: Output voltage across 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 battery charges correctly during operation, do the following:
Notes: Before you begin, install a discharged battery pack or battery pack that less than 50% of the total
power remaining in the computer.
1. If the battery status indicator does not turn on, remove the battery pack and let it return to room
temperature.
2. Reinstall the battery pack.
3. If the indicator still does not turn on, replace the battery pack.
4. If the indicator still does not turn on, replace the system board. Otherwise, refer to “Checking the battery
pack” on page 31 to check the original battery pack.
Checking the battery pack
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: Open the Power Manager program and click the Battery tab.
• For Windows 8: Open the Lenovo Support program and click Battery Health , or open the Lenovo
Settings program and click Power .
Note: If the battery pack becomes hot, it may not be able to charge. Remove it from the computer and leave
it at room temperature for a while. After it cools down, reinstall and recharge it.
To check the battery pack, do the following:
1. Power off the computer.
2. Remove the battery pack and measure the voltage between battery terminals 1 (+) and 7 (-). See the
following figure:
Chapter 3
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General checkout
31