IBM ThinkPad TransNote, Hardware Maintenance Manual

Page: 35 / 150

Checking the backup battery
Do the following:
1. Power off the computer, and unplug the ac adapter
from it.
2. Remove the battery pack (for the removal procedure,
see “1010 Battery pack” on page 56).
3. Remove the backup battery (for the removal procedure,
see “1060 Backup battery and sub-battery” on
page 73).
4. Measure the voltage of the backup battery. See the
following figure.
Wire Voltage (V dc)
Red +2.5 to +3.2
Black Ground
v
If the voltage is correct, replace the system board.
v
If the voltage is not correct, replace the backup battery.
v
If the backup battery discharges quickly after
replacement, replace the system board.
Checking the sub-battery
Do the following:
1. Recharge the sub-battery; it might have been
discharged.
2. Power off the computer, and unplug the ac adapter
from it.
3. Remove the battery pack (for the removal procedure,
see “1010 Battery pack” on page 56).
4. Remove the sub-battery (for the removal procedure,
see “1060 Backup battery and sub-battery” on
page 73).
5. Measure the voltage of the sub-battery. See the
following figure.
Wire Voltage (V dc)
Red +6.0 to +9.0
Black Ground
v
If the voltage is correct, replace the system board.
v
If the voltage is not correct, replace the sub-battery .
v
If the sub-battery discharges quickly after replacement,
replace the system board.
Checkout guide
General descriptions
31