Sony PEG-TH55 - Manual (Page 126)

Customizing your CLIÉ™ handheld (Preferences) 126
Turning the Alarm LED on or off
You can set your CLIÉ handheld to flash its LED at a set time. If you turn the
Alarm Sound off and turn the Alarm LED on, you can use the alarm feature
without disturbing people around you.
1
Tap V at the top right of the Preferences screen, and select
[General].
2
Tap V next to [Alarm LED:], and select [On] or [Off].
Tip
[Alarm LED:] is set to [On] by default.