哈曼卡顿Harman-Kardon-AVR-XXXX-维修手册

harman/kardonTECH TIPSTroubleshooting tips and solutions to common service problemsT1P#HKTT2004-03Isolating audio problems in an AVR receiverUsing 6/8 Direct InModels covered:The following charts are used to help the tech quickly isolateaudio problems in an AVR receiver.Use the followingAVR210AVR310procedures to help find what is working,then to quickly locateAVR220AVR320the problem area.AVR520AVR225Equipment needed:AVR125AVR525AVR130AVR2301 set of(RCA)Y adaptors.Function/signal generator.AVR330AVR430Oscilloscope.AVR630Procedure:1)Do a factory reset of the receiver.(This will eliminate any common micro processorproblems.)Reset List can be found near the last page or check the servicewebsite;www.harmanservice.com for the latest info.2)Print the block diagram from the service manual.3)With no inputs or speakers attached to the AVR turn on the receiver and turn thevolume all the way down.4)Turn unit off.5)Hook up an oscillator to the 6/8 Direct in jacks using the Y adaptors.Adjust theoscillator to about Odb (.775Volts RMS).6)Hook up an oscilloscope to monitor the line out jacks.Or,if there are no line out(preamp out)jacks monitor the input to the power amps or the speaker outs.(AVR125,225,130 do not have preamp out jacks)7)Turn the AVR on.Select 6 or 8 direct in,depending on the receiver.8)Slowly tum the volume control up until you can easily measure the voltage at the lineout jacks.(-40 to-25dbHarman Consumer Group 250 Crossways Park Dr.Woodbury,New York 11797Email Techsupport@harman.com