Cortelco 2757 - Manual (Page 50)

50
2. Press ‘Up’ or ‘Down’ until ‘3. Settings’ is selected, then press ‘Select’.
3. Press ‘Up’ or ‘Down’ until ‘3. Contrast’ is selected, then press ‘Select’.
4. Press ‘Up’ to make the displayed messages darker. Press ‘Down’ to make the displayed
messages lighter. Press ‘Save’ keep the new settings.