User Guide

Battery temperature is estimated by measuring separate battery temperature NTC via the BTEMP line, which
is located on the transceiver PWB, at a place where the phone temperature is most stable.
For service purposes, the device SW can be forced into local mode by using pull down resistors connected to
the BSI line.
User interface
Display interface
Display features:
• Up to 16M colors within 352 x 416 pixels
• Partial display function Power saving by pausing display process on part of the screen.
The display has two different operating modes:
1 Normal mode, Full screen, up to 16M colours
2 Partial mode, 260k colors but only part of the display is active with 8 colours
The interconnection between the LCD module and the Nokia engine is implemented with a 40-pin board-to-
board connector.
In partial mode all signalling is done via serial interface between display and application processor.
The display module does not require any tunings in service.
Keyboard
The device keyboard is connected to the main PWB with a board-to-board connector.
The keymatrix has six rows and four columns. The voice key on the main PWB and the navigation key are
connected to the same keymatrix.
Row /
Column
Col 0 Col 1 Col 2 Col 3 Col 4 Col 5
Row 0 Soft right End 3 6 9 #
Row 1 Pen Clear 2 5 8 0
Row 2 Soft left Send 1 4 7 *
Row 3 Application Joystick
Enter
Joystick
Left
Joystick
Up
Joystick
Down
Joystick Right
Row 4 Volume
Up
Volume
Down
Voice
Display and keyboard backlight
The device has one LED Driver (SMPS) that is used to drive both display and keyboard LEDs.
The LED driver consists of two LED chains: display LED chain and keyboard LED chain. Both chains contain four
LEDs, eight in total.
The current adjustment of the driver is done from the display LED branch. The keyboard current also depends
on the display brightness.
Typically, keyboard LEDs are turned ON only in dark ambient lighting conditions.
RM-49
Nokia Customer Care System Module
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