Testing the AC Adapter:
If the Power-On
indicator is not on, check the power cord of the AC adapter
for proper installation and continuity.
1. If any noise can be heard from the AC adapter when
it is plugged into line voltage, replace the AC adapter
with a new one.
If no noise can be heard from the adapter, go to Step
3.
2. If the noise still comes from the new AC adapter,
suspect the computer. Replace the AC adapter with
the original one, then go to the next step. If no noise
comes from the new adapter, the original adapter has
the problem.
3. Unplug the AC adapter cable from the computer and
measure the output voltages at the plug of the AC
adapter cable. Connect the minus lead of the
volt-ohm meter to pin 3 during the measurement.
4
2
1
3
If the voltages are not correct:
1. Unplug the AC adapter from the ac power outlet
and leave it for a few minutes.
2. Plug the AC adapter into the ac outlet.
3. Measure the output voltages of the AC adapter.
4. If the voltages are still not correct, replace the
AC adapter.
If the voltages are OK, plug the cable into the
computer and try the failing operation again.
If the problem still remains, replace the voltage converter.
If the problem disappeared, suspect the installation and
continuity of the AC adapter cable.
Pin
Voltage (V dc)
1
+
18 to
+
22
2
+
17 to
+
21
3
GND
4
Communication GND
120
IBM Mobile Systems HMM - Volume 1
