Connectivity Troubleshooting; Introduction To Connectivity Module Troubleshooting; Issue - Nokia RM-824 Service Manual

RM-824; RM-825; RM-826
BB Troubleshooting Guide

Connectivity troubleshooting

Introduction to connectivity module troubleshooting

The WCN3660 analog device supports WLAN 2 and 5 GHz, BT and FMRX. The FM RX & TX are not supported in
the product. The baseband part of the connectivity functions is integrated into MSM8960. The Bluetooth and
WLAN 2 GHz share the common front-end parts and FM Rx only uses headset wiring as an antenna. The
Bluetooth and WLAN 2 GHz path is connected to WLAN 5 GHz path with a diplexer, only one antenna feed is
needed for 2G and 5G signals. Transmitting output power level is changed according to data rate. The highest
power levels are provided in 802.11b data rates.
The BT BB interface can be logically divided into a 2-line digital serial interface that supports Rx/Tx and single-
wire serial bus (SSBI) for status and control. The WLAN BB interface can be logically divided into a 4-line
analog baseband interface and a 5-line digital command and control interface.
The WCN3660 device uses a 48.0 MHz clock from an external crystal (B6300).
The PMIC Asic supplies the whole WCN3660 solution, 1.8V, 1,3V and 3.0V. The WCN3660 has also an on-chip
LDO regulator to provide power supply to the WCN3660 1.2 V digital core. The integrated LDO input voltage
is applied from the VDD_XO_1P8 voltage.
The following figure shows a top level block diagram of the WCN3660 module.
Figure 5 WCN3660 block diagram
GNSS and WLAN/BT antennas
The GNSS and WLAN/BT antennas are laser deposited on a plastic carrier and then glued into the upper-left
side (GNSS) and the right upper corner (WLAN/BT) of the backside of the unibody. The WLAN 2 GHz/Bluetooth
and WLAN 5 GHz are connected to the same dual band antenna.
The antenna positions are presented in the following figure.
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