Ambient Light Detector; General Notes - Nokia NHL-2NA Series Troubleshooting Instructions

NHL-2NA

Ambient Light Detector

General Notes

Ambient light sensor problems can be found during the calibration process or as prob-
lems with the display backlight and grip LEDs. The problem can also be in the NTC-resis-
tor, which is used for temperature compensation of the ambient light detector. Before
starting troubleshooting according to these instructions, it must be ensured that the
problem really is in the ambient light detector. Other possibility is e.g. UI-module or
backlight powering itself. This can be checked easily, because light sensor can be turned
off.
Calibration of the Ambient Light Detector is needed always, when the phototransistor is
replaced.
Calibration system is described in chapter "Service Software Instructions".
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Figure 9: Ambient light detector calibration tool
¤Nokia Corporation
CCS Technical Documentation
Issue 1 07/02