Kenwood NX-800H Service Manual

Also see for NEXEDGE NX-800 series: Brochure Function reference Instruction manual Instruction manual Specifications

NX-800/800H41Fault diagnosis of the BGA (Ball Grid Array) ICOverview: A flowchart for determining whether or not the transceiver can be powered on (the LCD does not function even ifthe power switch is turned on) due to broken BGA parts.BGA parts: ASIC (IC510), DSP (IC502), FLASH (IC501), SRAM (IC503)When the BGA IC is problematic, please bring the printed circuit board (X57-7390-XX) in for service. Various ESN/default adjust-ment values are written on the printed circuit board for service. Additionally various ESN stickers are included. The power mod-ule (RA30H4452M123: K, RA55H4452M123: HK), short connector (E37-1180-05) and button type lithium battery (W09-0971-05)do not belong to the printed circuit board for service. Please use the part which has been attached to the printed circuit board.After the printed circuit board has been readjusted, please attach any ESN stickers to the chassis. When “ESN Validation” isused with NXDN Trunking, you must modify the ESN register.● Checking power supply voltageChecking voltagePoints to be checked Normal voltage33M IC402 (5 pin) 3.3V15M IC409 (5 pin) 1.5V33A IC408 (5 pin) 3.3V33BU D411 (Cathode side) 3.3VPower supply of each device is connected through the coil.[ASIC]33M: L903, 15M: L511, 33A: R603[DSP]33M: L503, 15M: L502[FLASH]33M: L501[SRAM]33BU: L522● Checking the clockChecking the clockPoints to be checked Normal voltage (3.3V)18.432MHz ASIC side R569 18.432MHzDSP side R511 18.432MHz32.768kHz IC504 (1 pin) or R545 32.768kHzWhen a normalvalue is confirmed.When a normalvalue is confirmed.● Checking the Reset/Control signalChecking the control signal input to the ASICPoints to be checked Normal voltageRST (RESET) IC506 (4 pin) 3.3V/BINT IC401 (1 pin) 3.3V/OVRB D403 (Cathode side) 3.3VChecking the ASIC input switch signal*Each signal is not masked by the setting of the FPU.The POWER key is pressed and held.Points to be checked Confirmed voltage/PSW (R619) 0VThe ignition key is kept ON.Points to be checked Confirmed voltage/IGN (R618) 0VRemove the R569, R511 and R545. If it oscillatesnormally, the DSP and ASIC may be broken.The BGA parts are not broken.Checking for an abnormal point33M has an abnormal voltage.[ASIC]Remove L508 to check the voltage of the 33M.If the voltage becomes normal, the ASIC is broken.[DSP]Remove L503 to check the voltage of the 33M.If the voltage becomes normal, the DSP is broken.[FLASH]Remove L501 to check the voltage of the 33M.If the voltage becomes normal, the FLASH is broken.15M has an abnormal voltage.[ASIC]Remove L511 to check the voltage of the 15M.If the voltage becomes normal, the ASIC is broken.[DSP]Remove L502 to check the voltage of the 15M.If the voltage becomes normal, the DSP is broken.33A has an abnormal voltage.[ASIC]Remove R603 to check the voltage of the 33A.If the voltage becomes normal, the ASIC is broken.33BU has an abnormal voltage.[SRAM]Remove L522 to check the voltage of the 33BU.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.● Checking the output signalfrom the ASICPoints to be checked Normal voltage/FRST R509 3.3VIf 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.When an abnormalvalue is confirmed.When an abnormalvalue is confirmed.When a normalvalue is confirmed.When a normalvalue is confirmed.When a normalvalue is confirmed.TROUBLE SHOOTING