Fm Radio; How The Fm Radio Works; Fm Radio Test; Fm Radio Troubleshooting - Nokia 3155i Troubleshooting Manual

3155/3155i (RM-41), 3152 (RM-61)
Baseband Description and Troubleshooting

FM Radio

How the FM Radio Works

The D2800 turns on the FM radio and sets the frequency using the CBUS serial interface
as the communication channel. A high frequency FM radio signal comes in through
RFIN1 Pin to the FM radio chip and gets demodulated into a low frequency signal and is
sent to the UEMEK for amplification. The amplified signal then gets routed back either to
the universal headset or to the system connector for the stereo headset.
POP PORT™ POP PORT™
System Connector System Connector
HSEARN HSEARN
HSEARP HSEARP
HSEARRN HSEARRN
HSEARRP HSEARRP
Figure 11: FM Radio (N356), Audio (N150), antenna, and digital interface connections

FM Radio Test

To hear the FM radio, you first connect headset to Pop-Port™ or UHJ ports because the
headset is an FM radio antenna. Connect the headset to UHJ port to control the FM radio
using Phoenix. If you connect a headset (such as HDS-3) to a Pop-Port™ connector, then
you cannot control the mobile terminal because you have already occupied the
connection port (Pop-Port™). In this case you have to have jumper wires on the
production test points (Fbus Tx/RX,GND).

FM Radio Troubleshooting

When troubleshooting the FM radio, make these common checks (see
• Check Power Supply VIO and VANA
• Check SleepCLK
• Check FMANT
• Check for activity on CBUS
• Check output of FM radio on VAFR and VAFL
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UEMEK UEMEK
audio audio
Amplifier Amplifier
40pF 40pF
68nH 68nH
©2005 Nokia Corporation
FM Radio FM Radio
FMClk FMClk
Xtal1 Xtal1
FMCtrlDa FMCtrlDa
Audio R Audio R
Data Data
FMCtrlClk FMCtrlClk
Audio L Audio L
Clock Clock
FMWrEn FMWrEn
W/R W/R
Rfin1 Rfin1
P P
100 100
Antenna signal Antenna signal
Company Confidential
TIKUEDGE TIKUEDGE
Sleep CLK Sleep CLK
CBUS_DA CBUS_DA
CBUS_CLK CBUS_CLK
CBUS_EN CBUS_EN
Figure 12):
ISSUE 1 07/2005