1-64 (No.RA016)SECTION 5TROUBLESHOOTING5.1 Fault Diagnosis of the BGA (Ball Grid Array) IC„Overview:A 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 parts:MPU/DSP (IC702), mobile DDR (IC703), Flash memory (IC705)When the BGA IC is problematic, please bring the printed circuit board (XC1-0321-81) in for service. Various ESN/ default adjust-ment values are written on the printed circuit board for service.Additionally various ESN stickers are included. (Please refer to "5.3 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 voltagePoints to be checkedPoints to be checkedPoints to be checkedPoints to be checkedNormal voltageNormal voltageNormal voltage1.2V19.2MHz12M C511.8V18M IC433.3V1.8V3.3V33M IC35 (1 pin)1.8V18M_3 IC701 (1 pin)Power supply of each device is connected through the coil.[MPU/DSP]12M: L705, L706, L70818M: L710, L71133M: L712[mobile DDR]18M: L717[Flash Memory]33M: L71818M_3: L719Checking the clockChecking the clockNormal voltage (1.2V)19.2MHzMPU/DSP side R780When a normalvalue is confirmed.When a normalvalue is confirmed.When a normalvalue is confirmed.When a normalvalue is confirmed.Checking the Reset/Control signalChecking the control signal input to the MPU/DSP/RST IC704 (4 pin)/BINT Q22 (6 pin)Checking the control signal output from the MPU/DSP If the /FRST is always 0V, the MPU/DSP is broken.The BGA parts are not broken.Checking for an abnormal point12M has an abnormal voltage.[MPU/DSP]Remove L705, L706 and L708 to check thevoltage of the 12M..If the voltage becomes normal, the MPU/DSPis broken.18M has an abnormal voltage.[MPU/DSP]Remove D705 to check the voltage of the Flashmemory side R747.When an abnormalvalue is confirmed.When an abnormalvalue is confirmed.When an abnormalvalue is confirmed.When an abnormalvalue is confirmed./FRSTChecking battery voltagePoints to be checked Normal voltage6~9V+B CN2The BGA parts are not broken.If the CN2 is less than 6V, charge the battery.When an abnormalvalue is confirmed.When a normalvalue is confirmed./PSW Q21 (3 pin) 3.3VFlash memory side D705 1.8VRemove L710 and L711 to check the voltageof the 18M.If the voltage becomes normal, the MPU/DSPis broken.[mobile DDR]Remove L717 to check the voltage of the 18M.If the voltage becomes normal, the mobileDDR is broken.33M has an abnormal voltage.[MPU/DSP]Remove L712 to check the voltage of the 33M.If the voltage becomes normal, the MPU/DSPis broken.[Flash memory]Remove L718 to check the voltage of the 33M.If the voltage becomes normal, Flash memoryis broken.If the voltage is not corrected, there is a problemother than the BGA parts.If the voltage becomes abnormal, Flash memoryis broken.18M_3 has an abnormal voltage.[Flash memory]Remove L719 to check the voltage of the 18M_3.If the voltage becomes normal, Flash memoryis broken.
