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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 be different 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 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.
Perform operational charging. If the battery status indicator or icon does not turn on, replace the battery pack.
If the charge indicator still does not turn on, replace the system board. Then reinstall the battery pack. If it is
still not charged, go to the next section.
Checking the battery pack
Battery charging does not start until the Power Manager battery gauge shows that less than 96% of the total
power remains; under this condition the battery pack can charge to 100% of its capacity. This protects the
battery pack from being overcharged or from having a shortened life.
To check your battery, move your cursor to the Power Manager battery gauge icon in the icon tray of the
Windows taskbar and wait for a moment (but do not click), and the percentage of battery power remaining
is displayed. To get detailed information about the battery, double-click the Power Manager Battery
Gauge icon.
Checking the backup battery
To check the backup battery, do the following:
1. Disable the built-in battery. See “Disabling the battery pack in the UEFI BIOS” on page 58.
2. Remove the backup battery (see “1080 Backup battery” on page 71).
3. Measure the voltage of the backup battery. See the following gure.
Wire
Voltage (V dc)
Red +2.5 to +3.2
Black
Ground
• If the voltage is correct, replace the system board.
• If the voltage is not correct, replace the backup battery.
• If the backup battery discharges quickly after replacement, replace the system board.
Chapter 3. General checkout 29