(No.RA018)1-97Verify the reference clock for the BT/GPS.(BT_CLK) Intersection ofC850 and R861: Sine waveform,19.2MHz, 0.2 to 1.2 Vp-p[The reference clock circuitfor the BT/GPS is faulty].Verify the BT/GPS controlsignal (RXD2).CP851 (1 pin): Square waveformUART data of 3.3V logic.Baud rate:Default: 115.2kbpsAfter: 3.967Mbps.Check the PCB side B (c).Verify the BT/GPS controlsignal (TXD2).CP851 (2 pin):Square waveform UART dataof 3.3V logic.C850, R861, R862.Replace any abnormal parts.Verify the LNA power supplyVDD_TCXO (G1 pin) of IC850(Intersection of C855 and R862): 1.8V[The power supply line circuitfor LNA is faulty]Replace any abnormal parts.[VDD_TCXO (G1 pin) ofIC850 is faulty]Replace the PCBVerify the BT/GPS controlsignal (18BT_HCI_RX).IC852 (8 pin):Square waveform UART dataof 1.8V logic.Baud rate:Default: 115.2kbpsAfter: 3.967Mbps.[MPU/DSP (IC702) is faulty]Replace the PCB.[The 18BT_HCI_RX (TXD2)line circuit is faulty]Verify the BT/GPS controlsignal (18BT_HCI_TX).IC852 (8 pin):Square waveform UART dataof 1.8V logic.[BT/GPS IC (IC850) is faulty]Replace the PCB.Check the PCB side B.Check the PCB side B.[The RXD2 (18BT_HCI_TX)line circuit is faulty]Replace the CP851, IC852, R858.Verify the LNA ENABLE.IC851 (6 pin): 1.8V[The LNA ENABLE line is faulty]Visual check of the R860(Whether not damaged).Replace any abnormal parts[GPS_EXT_LNA_EN(H6 pin) of IC850 isfaulty]Replace the PCB.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 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.When an abnormalcondition is confirmed.When an abnormalcondition is confirmed.When an abnormalcondition is confirmed.When a normalcondition is confirmed.When a normalcondition is confirmed.Visual check of the PCB side A parts(Whether not damaged)Visual check of the C855, R862 andR851 (Whether not damaged).Replace the CP851, IC852, R858.
