Power System Checkout; Checking The Ac Adapter; Checking Operational Charging - Lenovo G555 Hardware Maintenance Manual

Power system checkout

To verify a symptom, follow the steps below:
1. Turn off the computer.
2. Remove the battery pack.
3. Connect the AC adapter.
4. Make sure that power is supplied when you turn on the computer.
5. Turn off the computer.
6. Disconnect the AC adapter and install the charged battery pack.
7. Make sure that the battery pack supplies power when you turn on the
If you suspect a power problem, see the appropriate one of the following power
supply checkouts:
• "Checking the AC adapter " on page 23
• "Checking operational charging" on page 23
• "Checking the battery pack " on page 24

Checking the AC adapter

You are here because the computer fails only when the AC adapter is used.
•
•
To check the AC adapter, follow the steps below:
1. Unplug the AC adapter cable from the computer.
2. Measure the output voltage at the plug of the AC adapter cable. See the
Note: Output voltage for the AC adapter pin No. 2 may differ from the one you
are servicing.
3. If the voltage is not correct, replace the AC adapter.
4. If the voltage is acceptable, do the following:
•
•
Note: Noise from the AC adapter does not always indicate a defect.

Checking operational charging

To check whether the battery charges properly during operation, use a
discharged battery pack or a battery pack that has less than 50% of the total
power remaining when installed in the computer.
computer.
If the power-on indicator does not turn on, check the power cord of the AC
adapter for correct continuity and installation.
If the computer does not charge during operation, go to
operational charging".
following figure:
2
Replace the system board.
If the problem continues, go to
Pin Voltage (V DC)
1 +20
2 0
1
"Lenovo G555" on page 29.
General checkout
"Checking
23