Lenovo 28472PU Remove the backup battery see “1130 Backup battery” on page, Red + Black, Ground

4.Remove the backup battery (see “1130 Backup battery” on page 102).

5.Measure the voltage of the backup battery. See the following figure.

Red (+)

Black (-)

Wire	Voltage (V dc)
Red	+2.5 to +3.2
Black	Ground

vIf the voltage is correct, replace the system board.

vIf the voltage is not correct, replace the backup battery.

vIf the backup battery discharges quickly after replacement, replace the system board.

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