v If the power-on indicator does not turn on, check the
power cord of the AC Adapter for correct continuity and
v If the operational charge does not work, go to "Checking
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 not correct, replace the AC Adapter.
If the voltage is within the range, do the following:
v Replace the system board.
v If the problems still persist, go to "Undetermined
Problems" on page 52.
Note: An audible noise from the AC Adapter does not
always indicate a defect.
Checking operational charging
To check operational charging, use a discharged battery
pack (Battery ASM) or a Battery ASM that has less than
50% of the total power remaining when installed in the
Perform operational charging. If the battery status indicator
or icon does not turn on, remove the Battery ASM and let it
return to room temperature. Reinstall the Battery ASM. If
the charge indicator or icon still does not turn on, replace
the Battery ASM.
If the charge indicator still does not turn on, replace the
system board. Then reinstall the Battery ASM. If the
reinstalled Battery ASM is not charged, go to the next
ThinkPad R30 and R31 HMM
Voltage (V dc)
15.5 V. - 17.0 V.