Denon MC6000MK2EM Service Manual page 54

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 amplifier (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 figure 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 figure 1-9
1-9 U755 PIN 1
1-9 U755 PIN 4
1-9 U755 PIN 2
54
1-9 U755 PIN 3