IBM ThinkPad 340 Series Hardware Maintenance Manual page 218

Pin
1
2
If the voltage is correct, replace the system
board. If the problem is not corrected, go to
"Undetermined Problems" on page 227.
If the voltage is not correct, go to the next step.
2. Unplug the AC Adapter cable from the ac power
outlet and wait five minutes or longer to allow the
over voltage protection circuit to be fully discharged
and initialized.
3. Plug the AC Adapter cable into the ac power outlet.
4. Measure the output voltage of the AC Adapter.
5. If the voltage is still not correct, replace the AC
Adapter.
Note: An audible noise from the AC Adapter does not
always indicate a defective adapter.
Checking Operational Charging:
operational charging, use a discharged battery pack or a
battery pack that shows a yellow or orange battery status
indicator when it installed in the computer.
Perform operational charging. If the battery status
indicator turns orange and the battery charging indicator
turns green within two minutes, replace the AC Adapter.
Checking the Battery Pack:
not start until the Fuel-Gauge shows that less than 90% of
the total power remains; with this condition the battery
pack will charge to 100% of its capacity. This protects the
battery pack from being over-charged or having a
shortened life.
Notes:
a. Models 355x and 360x battery pack does not
contain a microprocessor. In the following,
ignore any reference to the storage switch.
b. Before you perform the following procedure,
check the following:
1. Power-off the computer.
2. Remove the battery pack and measure the voltage
between battery terminals 1 (+) and 4 (−). See the
following figure.
Note: The following figure shows the battery for the
Model 370C, 750x, 755C, and 755Cs. The
battery for Models 355x and 360x, do not
have the storage switch, but the battery
terminals are the same.
208
IBM Mobile Systems HMM
The correct battery pack is used for the
model.
The storage switch set to on (|).
Voltage (V dc)
+19.0 to +21.0
Ground
To check
Battery charging will