Nokia NHL-2NA Series Troubleshooting Instructions page 41

CCS Technical Documentation
1 Set light sensor sensitivity to minimum. Illuminate sensor from close range with
very bright light.
2 Sensor ADC-reading should be <500 in bright light and in total darkness >900.
3 Check that resistance between sensor collector and VFLASH1 is 22kΩ (R131).
Check that resistance between collector and emitter of the ambient light sensor
changes, when illumination on the sensor (from ~5kΩ in high illuminance to
~500kΩ in total darkness) (V130). If phototransistor has to be replaced, the
detector has to be calibrated. Calibration can be done only with TDS-11 light
source.
4 NTC ( R132) resistance at room temperature is ~47kΩ.
5 Check following points: is opening on the black paint in the A-cover covered; is
light guide (integrated in the A-cover) broken?
Issue 1 07/02 ¤Nokia Corporation
NHL-2NA
Page 35