Checking The Ac Power Adapter - Lenovo ThinkPad 10 Hardware Maintenance Manual

3. Clear Complementary Metal Oxide Semiconductor (CMOS) by inserting a straightened paper clip into
the emergency reset hole and pressing the Windows button at the same time.
4. Press the power button. If the tablet cannot be turned on, continue with the next step.
5. Connect the ac power adapter and press the power button.
• If the tablet is turned on, disconnect the ac power adapter from the tablet. If the tablet turns off, it
means that the built-in battery fails.
• If the tablet cannot be turned on, replace the built-in battery with another one. If the tablet can start
up with the new battery installed, it means that the original battery fails.

Checking the ac power adapter

When you use the ac power adapter to charge the tablet but no power is charged, see the instructions in this
topic to check the ac power adapter.
To check the ac power adapter, do the following:
1. Disconnect the ac power adapter from the tablet.
2. Measure the output voltage at the plug of the ac power adapter. Refer to the following illustration:
3. If the voltage is not correct, replace the ac power adapter.
4. If the voltage is acceptable, replace the system board.
3
2
(12V)
1
Pin
Voltage (V dc)
1 +12
2 0
3
Ground
.
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