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Nokia RM-313 Service Manual: Ambient Light Sensor; Keyboard

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System Module
Figure 54 Side key illumination circuitry

Ambient Light Sensor

Ambient Light Sensor is located in the UI/Slide module, in the upper part of the phone. It consists of the
following components:
• Lightguide (part of UI/Slide module cover).
• Ambient Light Sensor (ALS). ALS is logarithmic, which response to light is similar to human eye. ALS is
located on UI-FPC and it is not a spare part.
• Analog switch N4400, to turn on operating voltage VAUX to ALS only when needed.
• Pull-down resistor R4400 to convert current signal to voltage.
Ambient Light Sensor information is used to control backlights of the phone. Keyboard backlight is turned
OFF, when they are not needed. Display backlight is dimmed, when environment lighting is dark. Outdoors,
when environment is bright, display backlight is turned off. Ambient Light Sensor is calibrated in production.
In service points, calibration is not possible.


The device has two separate keyboards:
• S60 keyboard
• ITU keyboard
The S60 keyboard is assembled on the UI/slide module. If there's failure on this part, the whole module has
to be replaced. ITU keyboard pads are placed directly on the system/RF module.
ITU keyboard is visible, when display is moved upwards. Keypads are on the system/RF module. System/RF
module includes also side keys (Volume Keys, Imaging Key and 2-position camera key)
Page 6 –26
Issue 1
Copyright © 2007 Nokia. All rights reserved.




This manual also for:

N82, L3, L4

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  • Pavel Kraemer Dec 31, 2016 03:20:
    I cannot find how to switch off front flash on NOKIA 230.
    Pleas​e inform to