Kenwood NX-300 Service Manual

Also see for NEXEDGE NX-300: Brochure Instruction manual Instruction manual Instruction manual Instruction manual

Contents

NX-300 ADJUSTMENT30Fault diagnosis of the BGA ICOverview: A flowchart for determining whether or not the transceiver can be powered on (the LCD does not function even if thepower switch is turned on) due to broken BGA parts.BGA parts• ASIC (IC108)• DSP (IC102)• FLASH (IC101)• SRAM (IC103)● Checking power supply voltageChecking voltagePoints to be checked Normal voltage33M IC404 (5 pin) 3.3V15M IC405 (5 pin) 1.5V33A IC406 (5 pin) 3.3V31BU IC416 (3 pin) 3.1VPower supply of each device is connected through the coil.[ASIC]33M:L714 15M:L715 33A:L716[DSP]33M:L712 15M:L711[FLASH]33M:L717[SRAM]31BU:L710● Checking the clockChecking the clockPoints to be checked Normal voltage (3.3V)18.432MHz ASIC side R158 18.432MHzDSP side R159 18.432MHz32.768kHz IC106(1 pin) 32.768kHzWhen a normal valueis confirmed.● Checking theReset/Control signalChecking the control signal input to the ASICPoints to be checked Normal voltageRESET IC105 (4 pin) 3.3V/BINT Q401 (6 pin) 3.3V/PSW Q402 (3 pin) 3.3VChecking the control signal output from the ASICPoints to be checked Normal voltage/FRST C110 3.3VThe BGA parts are not broken.If the /FRST is always 0V, the ASIC is broken.If the /FRST repeats 3.3V and 0V at intervals,the ASIC, FLASH and SRAM may be broken.Checking an abnormal point33M has an abnormal voltage.[ASIC]Remove L714 to check the voltage of the 33M.If the voltage becomes normal, the ASIC is broken.[DSP]Remove L712 to check the voltage of the 33M.If the voltage becomes normal, the DSP is broken.[FLASH]Remove L717 to check the voltage of the 33M.If the voltage becomes normal, the FLASH is broken.15M has an abnormal voltage.[ASIC]Remove L715 to check the voltage of the 15M.If the voltage becomes normal, the ASIC is broken.[DSP]Remove L711 to check the voltage of the 15M.If the voltage becomes normal, the DSP is broken.33A has an abnormal voltage.[ASIC]Remove L716 to check the voltage of the 33A.If the voltage becomes normal, the ASIC is broken.31BU has an abnormal voltage.[SRAM]Remove L710 to check the voltage of the 31BU.If the voltage becomes normal, the SRAM is broken.If the voltage is not corrected, there is a problemother than the BGA parts.When an abnormalvalue is confirmed.When an abnormalvalue is confirmed.When an abnormalvalue is confirmed.When an abnormalvalue is confirmed.When a normal valueis confirmed.When a normal valueis confirmed.When a normal valueis confirmed.