IBM THINKPAD 760C/CD (9546) User Manual

Page 285

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“Checking the Backup Battery” on page 275.

Checking the AC Adapter:

You are here

because the computer fails only when the AC Adapter is
used.

If the power problem occurs only when the port
replicator is used, replace the replicator.
If the power-on indicator does not turn on, check the
power cord of the AC Adapter for correct continuity
and installation.
If the operational charge does not work, go to
“Checking Operational Charging.”

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.

(16 - 10 V)

Replace the system board.
If the problem is not corrected, go to
“Undetermined Problems” on page 290.
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:

To check

operational charging, use a discharged battery pack or a
battery pack that has less than 50% of the total power
remaining when installed in the computer.

Pin

Voltage (V dc)

1

+

14.5 to

+

17.0

2

Ground

ThinkPad 560 (2640)

273

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