If the power-on indicator does not turn on, check the
power cord of the AC Adapter for correct continuity
and installation.
1. Unplug the AC Adapter cable from the computer and
measure the output voltage at the plug of the AC
Adapter cable. See the following figure:
If the voltage is correct, make sure the
connection between DC/DC card and system
board is not loose.
Replace the DC/DC card.
If the problem is not corrected, replace the
system board.
If the problem persists, go to “Undetermined
Problems” on page 561.
If the voltage persists, go to the next step.
2. Unplug the AC Adapter cable from the ac power
outlet and wait 5 minutes or longer to allow the
overvoltage 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 defect.
Checking the Battery Pack: If the battery pack
has a problem, do 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:
Pin Voltage (V dc)
1+15.5 to +17.0
2 Ground
534 IBM Mobile Systems HMM