Amp Adjustments; Test Mode - Yamaha RX-777 Service Manual

AMP ADJUSTMENTS

Confirmation of Idling Current
• Right after power is turned on, confirm that the voltages of between R111-R135 and R112-R136 are between 0.1mV and
10mV.
• If they exceed 10mV, cut R175, R176. Then reconfirm they are between 0.1mV and 10mV.
L ch
0.1mV ~ 10.0mV
(DC)
Note)
• If R175 (L ch) or R176 (R ch) have already been cut off and idling current does not flow, reconnect R175 (1kΩ) or R176 (1kΩ).
• Q117 and Q118 are transistors for temperature correction. Apply silicone grease to the contact surface with the heat sink.

TEST MODE

CAUTION: Before setting to the TEST mode, write down the existing preset memory content of the Tuner in a table as
shown below. (This is because setting to the TEST mode will cause the memory content to be as factory set,
i.e., all the preset memory by the user will be erased.)
Preset group
A
B
C
D
E
Factory preset memory content
Preset group
A/C/E U, C
B/D U, C
R175 (L ch)
R176 (R ch)
P1 P2 P3
P1 P2
87.5 MHz 90.1 MHz 95.1 MHz
A 87.5 MHz 90.1 MHz 95.1 MHz
630 KHz 1080 KHz 1440 KHz
A 630 KHz 1080 KHz 1440 KHz
R111 R112
R175 R176
R135 R136
Cut off
P4 P5
P3 P4 P5
98.1 MHz 107.9 MHz 88.1 MHz 106.1 MHz 107.9 MHz
98.1 MHz 108.0 MHz 88.1 MHz 106.1 MHz 108.0 MHz
530 KHz 1710 KHz
531 KHz 1611 KHz
RX-777
R ch
0.1mV ~ 10.0mV
(DC)
P6 P7 P8
P6 P7 P8
900 KHz 1350 KHz 1400 KHz
900 KHz 1350 KHz 1404 KHz
6