Kenwood NXR-700 Service Manual

Also see for NEXEDGE NXR-700: Brochure Instruction manual Service manual Instruction manual Instruction manual

Contents

NXR-700741-2. Hardware Traceability (Method 1)■ Procedure for IC703 (Main MPU) traceabilityPower Source VoltageTest Point Normal Output VoltageIC329 (pin 4) 3.3VDCIC306 (pin 3) 1.5VDCCorrect conditionConfi rmation of Clock frequencyTest Point Proper FrequencyR725 25.8048MHz(either end of R725 is OK)Correct conditionConfi rmation of Reset controlTest Point Normal VoltageIC726 (pin 4) 3.3VDCCorrect conditionParts other than IC703 are malfunctioning.■ Traceability Procedure of IC324 (TX Vocoder_DSP)Confi rmation of Power Source VoltageTest Point Normal Output VoltageIC307 (pin 1) 1.5VDCIC15 (pin 3) 3.3VDCCorrect conditionConfi rmation of Clock frequencyTest Point Proper FrequencyR679 12.288MHz(either end of R679 is OK)Correct conditionConfi rmation of Reset controlTest Point Normal Output VoltageR521 3.3VDC(either end of R521 is OK)Correct conditionParts other than IC324 are malfunctioning.Confi rmation of IC329 (pin 5) outputRemove R711 and R721.If the voltage is 3.3VDC, IC703 is malfunctioning.Confi rmation of IC306 (pin 3) outputRemove R715 and R716.If the voltage is 1.5VDC, IC703 is malfunctioning.If 25.8048MHz oscillation cannot be confirmed:X700 is malfunctioning or a component aroundX700 is malfunctioning.Clock oscillation amplitude is weak:The drive circuit for IC703 is malfunctioning.Check the voltage of pin 1 and pin 2 of IC726:Pin 1 = 3.3VDC. If not, IC325 is malfunctioning.Pin 2 = 3.3VDC. If not, IC708 is malfunctioning.Confi rmation of IC307 (pin 1) outputRemove R486 and if 1.5VDC, IC324 is malfunction-ing.Confi rmation of IC15 (pin 3)Remove R488 and if 3.3VDC, IC324 is malfunction-ing.If 12.288 MHz oscillation cannot be confirmed:X300 is malfunctioning or a component aroundX300 is malfunctioning.The clock oscillation amplitude is weak.The drive circuit for IC324 is malfunctioning.Remove R521 and then measure the voltage ofIC325 side:If not 3.3VDC, IC325 is malfunctioning.Remove R521 and confirm the voltage of pad sideof IC325:If the voltage is 3.3VDC, IC324 is malfunctioning.AbnormalconditionAbnormalconditionAbnormalconditionAbnormalconditionAbnormalconditionAbnormalconditionTROUBLE SHOOTING