Fm Radio; How The Fm Radio Works; Fm Radio Test; Fm Radio Troubleshooting - Nokia 2255 Baseband Description And Troubleshooting

Nokia Customer Care

FM Radio

How the FM Radio Works

The UPP 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 UEMC for amplification. The amplified signal then gets routed back either to the
universal headset.
Figure 12: FM Radio (N356), Audio (N150), antenna, and digital interface connections

FM Radio Test

To hear the FM radio, you first connect headset to UHJ ports because the headset is an
FM radio antenna. Connect the headset to UHJ port to control the FM radio using
Phoenix. Using Phoenix change mobile terminal to local mode and launch the FM radio
component to hear FM radio output.

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 for an audio signal with a 800mv DC-offset
• If the audio signal not correct (with 800mv DC-offset), then check FM radio chip
for shorts, voids, and misalignments
ISSUE 1 10/2005
©2005 Nokia Corporation
Baseband Description and Troubleshooting
Company Confidential
2255 (RM-97)
Figure 13):
Page 15