User Guide

Backlights troubleshooting

Context

The device has three LED drivers. One of the drivers provides current for both displays and the upper keyboard

backlights. Two other LED drivers provide current for lower keyboard backlight. The upper keyboard backlight

can be turned OFF separately, but it cannot be turned ON without switching ON the display backlight

simultaneously. The lower keyboard backlight can be turned ON/OFF separately.

Main/cover display and upper keyboard backlight troubleshooting

RM-176

Nokia Customer Care BB Troubleshooting and Manual Tuning Guide

Page 6 –28 COMPANY CONFIDENTIAL Issue 1