3Com III Handbook page 58

If the telephone line you are using has Call Waiting, make sure
you selected the Disable call waiting option under Modem Sync
Phone Setup on your Palm III organizer and entered the correct
code.
Make sure the telephone line you are using is not noisy, which can
interrupt communications.
Make sure your modem resets before you try again. (Turn off your
modem, wait a minute, then turn it back on.)
General Troubleshooting
Palm III organizer does not turn on:
Adjust the contrast control.
Make sure batteries are installed properly.
Replace the batteries. If your Palm III organizer still does not
operate, try a soft reset; see "Resetting Your Palm III™ Organizer."
Low battery warning after replacing the batteries:
The battery warning message may appear immediately after
replacing the batteries. In addition, if you check the battery gauge
in the Applications Launcher immediately after replacing the
batteries, the gauge may start at "empty" and slowly rise to "full."
This is normal. It takes a few minutes for the battery gauge to
accurately show the condition of the batteries.
No sound:
Check the System Sound option in the General Preferences screen.
If the option is set to off, there will be no sound. See "General
Preferences" in the Applications Handbook for the Palm III Organizer
for more information.
Palm III organizer turns itself off:
Your Palm III organizer is designed to turn itself off after a period
of inactivity. This period can be set at one minute, two minutes or
three minutes. Check the "Auto-off after" setting in the General
Preferences screen, and change the setting if you need a longer
delay before the automatic shutoff feature activates. See "General
Preferences" in the Applications Handbook for the Palm III Organizer
for more information.
Page 54 Basic Handbook for the Palm III Organizer