1-94 (No.RA020)SECTION 5TROUBLESHOOTING5.1 Fault Diagnosis of the BGA (Ball Grid Array) ICOverviewA flowchart for determining whether or not the transceiver can be powered on (the LCD does not function even if the power switchis turned on) due to broken BGA parts.BGA partsMPU/DSP (IC706), mobile DDR (IC702), Flash memory (IC701)When the BGA IC is problematic, please bring the printed circuit board (XC1-0381-81/XC1-0400-11) in for service. Various ESN/default adjustment values are written on the printed circuit board for service.Additionally various ESN stickers are included. (Please refer to "5.4 Replacing Main Unit".)After the printed circuit board has been readjusted, please attach any ESN stickers to the chassis. When "ESN Validation" is used,you must modify the ESN register.Checking power supply voltageChecking the clockChecking the Reset/Control signalChecking voltagePoints to be checked12M C39 1.2V18M C64 1.8V33M IC5 (5 pin) 3.3V18M_3 IC9 (1 pin) 1.8VPower supply of each device is connected throughthe coil.[MPU/DSP]12M L714, L715, L71718M L720, L72133M L722[mobile DDR]18M L702[Flash Memory]33M L70018M_3 L724Checking for an abnormal point12M has an abnormal voltage.[MPU/DSP]Remove L714 and L715 and L717 to checkthe voltage of the 12M.If the voltage becomes normal, the MPU/DSPis broken.Note:A1(12M DC/DC Converter Device) is fragilein the scratch.Be careful when you touch this parts.18M has an abnormal voltage.[MPU/DSP]Remove L720 and L721 to check the voltageof the 18M.If the voltage becomes normal, the MPU/DSPis broken.[mobile DDR]Remove L702 to check the voltage of the 18M.If the voltage becomes normal, the mobile DDRis broken.33M has an abnormal voltage.[MPU/DSP]Remove L722 to check the voltage of the 33M.If the voltage becomes normal, the MPU/DSPis broken.[Flash Memory][Flash Memory]Remove L700 to check the voltage of the 33M.If the voltage becomes normal, Flash memoryis broken.18M_3 has an abnormal voltage.Remove L724 to check the voltage of the18M_3. If the voltage becomes normal,Flash memory is broken.If the voltage is not corrected, there is aproblem other than the BGA parts. *1Checking the clockPoints to be checked Normal voltage (1.2V)Normal voltageNormal voltage19.2MHz 19.2MHzMPU/DSP side R708The BGA parts are not broken.When an abnormalvalue is confirmed.When an abnormalvalue is confirmed.When an abnormalvalue is confirmed.When an abnormalvalue is confirmed.Checking the control signal input to the MPU/DSPPoints to be checked/RST D12 (Anode side) 1.8V/OVRB_OUT IC2 (12 pin) 3.1V/BINT IC2 (13 pin) 3.1VChecking the MPU/DSP input switch signalThe POWER key is pressed and held.Points to be checked Confirmed voltage/PSW_OUT IC2 (15 pin)The ignition key is kept ON.Points to be checked Confirmed voltage The BGA parts are not broken.Check the peripheral circuit of IC2. *2/IGN_OUT IC2 (9 pin) ON 0VON 0VWhen a normalvalue is confirmed.When a normalvalue is confirmed.When a normalvalue is confirmed.When a normalvalue is confirmed.
