Idling Current Adjustment - Marantz 74 PM52/00B Service Manual

'IDLING CURRENT ADJUSTMENT
(1) Before switching the power ON, set the Master Volume
control to the minimum position and the Balance and
Tone controls to the center positions. Also set semi-fixed
resistors R719 (L CH) and R720 (R CH) on PCB P701 to
the center positions.
(2) Each of the cement resistors R743 (L CH) and R744 (R
CH) on the PCB P701 is provided with three test points.
Connect a digital voltmeter, set for the DC voltage input,
to the test points at the two extremities of the three
test points of R743 or R744
(3) After the setup above, switch the power ON and adjust
semi-fixed resistor R719 (L CH) or R720 (R CH) on
PCB P701 according to the digital voltmeter reading.
The target setting value is 8 mV ( 22 mA ) for both the
L CH and R CH.
Please refer to the table below.
Elapsed time after power ON Idling current setting value
30 sec. — 1 min. 7.5 mV
T min. — 2 min, 8 mV
2 min. — 4 min. 8 mV
More than 4 min. 8mvV
Note on Safety:
Symbol @ Fire or electrical shock hazard. Only original
parts should be used to replace any part marked with
symbol &, Any other component substitution (other
than original type), may increase risk of fire or electrical
shock hazard,
MZ 2894