User Guide

Displays and keyboard backlight troubleshooting

Context

The device has one LED driver that provides current for both displays and keyboard backlights. The driver

gets the PWM signal from Tahvo. Because of the main display is transmissive, HW light dimming (controlled

by TAHVO GENOUT01) is also implemented. There is also a switch for selecting which display is lit on. It is not

possible to turn on both displays’ lights at the same time. The backlight brightness can be adjusted manually

in Phoenix.

RM-198

BB Troubleshooting and Manual Tuning Guide Nokia Customer Care

Issue 1 COMPANY CONFIDENTIAL Page 6 –25