Denon MC6000MK2EM - Page 54

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1-11NosoundoutputfromPHONES
Symptom: Audio is not output :
Diagnostic procedure:
1. Is a signal output to the DAC? U759:PHONES->PIN15 & PIN18
A. If it is, something is wrong with the analog -circuit block. Check if output amplier (U512: PHONES) is
working normally. Check if each MUTE transistor (Q550~Q553:PHONES)BASE PIN is -12V.
B. If it is not, something is wrong with the digital-circuit block. Check if there is CLOCK signal for
U759 :PHONE->PIN1 & PIN2 & PIN3 & PIN4, as gure 1-9.
1-12NosoundinputfromMIC1
Symptom: Audio is not input:
Diagnostic procedure:
1. Is a signal input to the ADC ? MIC(U752) ->PIN10
A. If it is not, something is wrong with the analog-circuit block. Check if OPA MIC(U513) is working
normally.
B. If it is, something is wrong with the digital-circuit block. Check if there is CLOCK signal for MIC(U752) -
>PIN2 & PIN4 & PIN7 & PIN8, as gure 1-9
1-9 U755 PIN 21-9 U755 PIN 1
1-9 U755 PIN 4
1-9 U755 PIN 3