Note: If the battery pack becomes hot, it may not be able to charge. Remove it

from the computer and leave it at room temperature for a while. After it
cools down, reinstall and recharge it.

To check the battery pack, do the following:

1. Power off the computer.
2. Remove the battery pack and measure the voltage between battery terminals 1,

2 (-) and 6, 7 (+). See the following figure:

2(-)
3
4
7(+)6(+)5
1(-)
Terminal Voltage (V dc)
1, 2 Ground (−)
6, 7 + 0 to + 16.8
3. If the voltage is less than +11.0 V dc, the battery pack has been discharged.

Note: Recharging will take at least 3 hours, even if the indicator does not turn

on.
If the voltage is still less than +11.0 V dc after recharging, replace the battery.
4. If the voltage is more than +11.0 V dc, measure the resistance between battery
terminals 3 and 2. The resistance must be 4 to 30 K .
If the resistance is not correct, replace the battery pack. If the resistance is

correct, replace the system board.

Checking the backup battery
Do the following:
1. Power off the computer, and unplug the ac adapter from it.
2. Turn the computer upside down.
3. Remove the battery pack (see “1010 Battery pack” on page 56).
4. Remove the backup battery (see “ 1110 Backup battery” on page 76).

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

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.

Checkout guide

32 MT 8747, 8749, 9440, 9441, 9442, 9443, and 9448