1-110 (No.RA015)5.3 Failure diagnosis of the Bluetooth sectionOverview:When the Bluetooth function does not operate, use this flowchart to determine the problem.I can not pair with the Bluetooth (BT) headset.NoYesMajor parts for a Bluetooth circuitBluetooth antenna (Connect on CN909)LC filter (L855)Bluetooth/GPS (IC850)Level conversion IC (IC852, IC853)TCXO 19.2MHz (X700)Clock Buffer (IC700)32.768kHz clock (X850)33BT Regulator (IC38)18BT Regulator (IC37)MPU/DSP IC (IC702)Replace any abnormal parts.Verify the BT/GPS power supply.(33BT) L862: 3.3VCheck the PCB side A.Check the PCB side A.Verify the ANT Matching Parts.Verify check to L863, C893, L855,C873.[The BT/GPS power supplyline 33BT circuit is faulty]Verify the PCB side A parts.C856, C860, C861, C870L862, C885, C890Replace any abnormal parts.Replace any abnormal parts.Check the PCB side B (a).Verify the BT/GPS power supply.(18BT) L861: 1.8V[The BT/GPS power supplyline 18BT circuit is faulty]Verify the PCB side A parts.C859, C852, C868, L861,C891, C844Check the PCB side B (b).Verify the BT/GPS controlsignal (/BT_SHUTDOWN).R853: 1.8V[MPU/DSP (IC702) is faulty]Replace the PCB.IC702 IC852 IC850UART UART L855IC853Shee t metalPCM PCMX700 IC700 X850MPU/DSPICBT/GPSICTCXO19.2MHz32.768 kHzClockLCFilterBluetoothAntenn aClockBufferLevelconversionICLevelconversionICMake sure the BT headset have enough power?Turn on your BT headset?Put your BT headset into pairing mode?Charge the BT headset. Turn on your BT headset and bring itwithin one to two meters.Try again pair with BT headset.Verify the contact of the BT internalantenna with the PCB.To reassembly correctly the BT antenna.If an antenna is defective, replace the BT internal antenna.When a normalcondition is confirmed.When a normalcondition is confirmed.When a normalcondition is confirmed.When a normalcondition is confirmed.When a normalcondition is confirmed.When an abnormalcondition is confirmed.When an abnormalcondition is confirmed.When an abnormalcondition is confirmed.When an abnormalcondition is confirmed.When an abnormalcondition is confirmed.When an abnormalcondition is confirmed.When an abnormalcondition is confirmed.
