Bluetooth And Fm Radio Troubleshooting; Introduction; Component Placement - Nokia RM-579 Service Manual

RM-578; RM-579
RF troubleshooting
4. Change power level (RF controls) and make sure the power reading follows accordingly.
Next actions
TX is failing and RX is OK: replace N7520
If you want to troubleshoot the other bands, change band with RF controls and set the communication
analyzer accordingly.

Bluetooth and FM radio troubleshooting

Introduction

The Bluetooth and FM radio receiver and transmitter are combined in the same ASIC, so these features are
all checked when troubleshooting (if supported). If the phone does not support the FM transmitter feature
there will be no FM TX discrete components or antenna.

Component Placement

The placement of Bluetooth and FM components and test probe points is shown below.
The Bluetooth antenna is product specific (PWB track, SMD antenna, clip on antenna, or antenna integrated
into phone covers) and is typically located near the side of the PWB. On phones with WLAN, the Bluetooth RF
signal is routed through a WLAN front-end module and a shared Bluetooth / WLAN antenna is used.
The FM receiver RF signal is routed through a product specific FM antenna matching circuit to the phone
headset connector. Typically, the FM receiver antenna matching circuit is located near to the phone headset
connector. The FM receiver audio signal is routed to the headset connector through the BB ASIC shared by
the phone audio functions.
The FM transmitter antenna is product specific and is typically integrated into the phone mechanics (for
example a loop antenna integrated into phone covers). The FM transmitter audio input signal is routed from
the phone BB section to the Bluetooth-FM ASIC.
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