Display And Keyboard Backlight - Nokia N72 Service Manual

RM-180
Nokia Customer Care System Module
Keyboard layout
Figure 99 Keyboard layout

Display and keyboard backlight

The device has one LED Driver (SMPS) that is used to drive both display and keyboard LEDs.
The LED driver consists of two LED chains: display LED chain and keyboard LED chain. Both chains contain four
LEDs, eight in total.
The current adjustment of the driver is done from the display LED branch. The keyboard current also depends
on the display brightness.
Typically, keyboard LEDs are turned ON only in dark ambient lighting conditions.
Page 9 –24 COMPANY CONFIDENTIAL Issue 1
Copyright © 2006 Nokia. All rights reserved.