Yealink SIP-T48G Administrator's Manual page 87

For SIP-T27P/T23P/T23G/T21(P) E2:
The default value is 30.
Web User Interface:
Settings->Preference->Backlight Time (seconds)
Phone User Interface:
Menu->Settings->Basic Settings->Display->Backlight->Backlight Time
To configure backlight via web user interface (take SIP-T23G IP phones for example):
1. Click on Settings->Preference.
2. Select the desired value from the pull-down list of Backlight Time (seconds).
3. Click Confirm to accept the change.
To configure backlight via phone user interface (take SIP-T23G IP phones for example):
1. Press Menu->Settings->Basic Settings->Display->Backlight.
2. Press or
Backlight Time field.
3. Press the Save soft key to accept the change.
To configure the backlight via web user interface (take SIP-T46G IP phones for example):
1. Click on Settings->Preference.
2. Select the desired value from the pull-down list of Backlight Inactive Level.
3. Select the desired value from the pull-down list of Backlight Active Level.
, or the Switch soft key to select the desired type from the
Configuring Basic Features
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