Nokia 3105 Servicehandbuch
RH-48
Troubleshooting — BB
CCS Technical Documentation
Page 22
©
2003 Nokia Corporation Confidential
Issue 1 11/2003
Figure 18: Charging circuity at the battery
Audio
The audio control and processing in RH-48 is provided by UEM, which contains the audio
codec, and UPP — which contains the MCU and DSP blocks, handling and processing the
audio data signals.
codec, and UPP — which contains the MCU and DSP blocks, handling and processing the
audio data signals.
The baseband supports three microphone inputs and two earpiece outputs. The micro-
phone inputs are MIC1, MIC2, and MIC3. MIC1 input is used for the phone's internal
microphone; MIC2 input is used for headsets (HDB-4). MIC3 is not used. Every micro-
phone input can have either a differential or single-ended AC connection to UEM circuit.
In RH-48, the internal microphone (MIC1) and external microphone (MIC2) for Toma-
hawk accessory detection are both differential. The microphone signals from different
sources are connected to separate inputs at UEM. Inputs for the microphone signals are
differential type. Also, MICBIAS1 is used for MIC1 and MICBIAS2 is used for MIC2.
phone inputs are MIC1, MIC2, and MIC3. MIC1 input is used for the phone's internal
microphone; MIC2 input is used for headsets (HDB-4). MIC3 is not used. Every micro-
phone input can have either a differential or single-ended AC connection to UEM circuit.
In RH-48, the internal microphone (MIC1) and external microphone (MIC2) for Toma-
hawk accessory detection are both differential. The microphone signals from different
sources are connected to separate inputs at UEM. Inputs for the microphone signals are
differential type. Also, MICBIAS1 is used for MIC1 and MICBIAS2 is used for MIC2.
Display and Keyboard
LEDs are used for LCD and keypad illumination in RH-48. There are two LEDs for LCD and
four LEDs for keypad. The signal used to drive the LED driver for the LCD and keyboard is
KLIGHT. This signal turns on the LED driver (N302).
four LEDs for keypad. The signal used to drive the LED driver for the LCD and keyboard is
KLIGHT. This signal turns on the LED driver (N302).
Color LCD is used in RH-48. Interface is using 9-bit data transfer. The interface is quite
similar to DCT3 type interface, except Command/Data information is transferred
together with the data.
similar to DCT3 type interface, except Command/Data information is transferred
together with the data.
The following figure is the waveform for LCD interface.
R200
.22 Ohms
N10
UEM Pins
M10
C201
1uF
C202
10nF
VBAT