IBM ThinkPad 340 Series Hardware Maintenance Manual page 413

Checking the Travel Quick Charger
1. Ensure that the battery pack is operating correctly.
(See "Checking the Battery Pack" on page 399.)
2. Connect the power cord to the Travel Quick Charger
and the other end to an ac power outlet. Ensure that
the power-on indicator is on.
If the power-on indicator does not turn on, check
the power cord for correct continuity and
installation.
If the problem is not corrected, replace the
Travel Quick Charger or the power cord.
3. Install the battery pack into the Travel Quick Charger.
If the charging indicator does not start blinking,
replace the Travel Quick Charger.
Checking the Backup Battery
1. Power-off the computer and unplug the AC Adapter
from the computer.
2. Open the keyboard, and remove the battery pack.
3. Remove the backup battery from the shield assembly.
4. Measure the voltage of the backup battery. See the
following figure.
Wire
Red
Black
If the voltage is correct, replace the system board.
If the voltage is not correct, the backup battery has
been discharged. Replace the backup battery.
If the backup battery discharges quickly after
replacement, replace the system board.
Checking the Standby Battery
1. Power-off the computer and unplug the AC Adapter
from the computer.
2. Open the keyboard, and remove the battery pack and
the diskette drive.
ThinkPad 755CE, 755CSE, 755CV, 755CX (9545)
Voltage (V dc)
+2.5 to +3.7
Ground
403