Idle Adjustment Procedures - Harman Kardon AVR435 Service Manual

AVR435/635
AVR435/635 IDLE ADJUSTMENT PROCEDURES
NO Signal/No Load
AC Line Voltage:120V/60Hz.230V/50Hz
1. MAIN AMP idle Adjustment
MAIN:VR71.VR72
SURROUND:VR73.VR74
1) After turning the unit ON wait at least 25 minutes before adjustment (to achieve normal power/Driver TR temperature)
2) Adjust the voltage value of primary&secondary of wafer to be 23mV by rotating the Potentiometer of each channel
CHANNEL
FRONT-L CH
FRONT-R CH
SURROUND-L CH
SURROUND-R CH VR74
The corresponding channels should be adjusted again following the above procedure, when these Transistors are replaced:
FRONT AMP: Q433.Q434.Q435.Q436.Q337.Q338.Q339.Q340
SURROUND AMP: Q329.Q330.Q331.Q332.Q333.Q334.Q335.Q336
2. CENTER/SURROUND BACK AMP idle Adjustment
CENTER:VR501
SURROUND BACK:VR201.VR301
1) After turning the unit ON wait at least 25 minutes before adjustment (to achieve normal power/Driver TR temperature)
2) Adjust the voltage value of primary&secondary of wafer to be 23mV by rotating the Potentiometer of each channel
CHANNEL
CENTER
SUR BACK-L CH
SUR BACK-R CH
The corresponding channels should be adjusted again following the above procedure, when these Transistors are replaced:
CENTER AMP: Q516.Q517.Q518.Q519
SUR BACK AMP: Q216.Q217.Q218.Q219.Q316.Q317.Q318.Q319
CAUTION
When POWER TR or DRIVER TR need replacement,
On the MAIN & SUPPLY BOARD, the following capacitors should be discharged for 30 seconds
with a 4.7 Ohm 10W resistor after turning unit OFF, to preventing possible damage from an electrical spark.
MAIN BOARD
SUPPLY BOARD
ADJUSTMENT MEASUREMENT
VR71 P801
VR72 P802
VR73 P803
P804
ADJUSTMENT MEASUREMENT
VR501 P501
VR201 P201
VR301 P301
C504.C505 AVR435 12000/63V
C571.C572 AVR635 15000/63V
C201.C202 AVR435 8200/63V
C201.C202 AVR635 10000/63V
VOLTAGE
23+/-2mV
23+/-2mV
23+/-2mV
23+/-2mV
VOLTAGE
23+/-2mV
23+/-2mV
23+/-2mV
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harman/kardon