Yamaha A-S700 Service Manual page 42

A B
A-S700
1
MAIN (1) P.C.B.
(Side A)
2
CB103
3
OPERATION (1)
(W801)
4
W101
5
W102
6
CB132
MAIN (4)
(CB282)
7
42
C D
MAIN (6) P.C.B.
(Side A)
IC101
CB101
# # #
Q122A Q124A Q122C
Q123A Q121A Q121C
# # #
Note) Those parts marked with "#" are not included in the P.C.B. ass'y.
MAIN (7) P.C.B.
(Side A)
IC102
CB102
E F G
#
Q124C
Q123C
#
CB128
MAIN (4)
(CB281)
W104
MAIN (3)
(CB272)
H I
Safety measures
• Some internal parts in this product contain high voltages and are dangerous. Be sure to
take safety measures during servicing, such as wearing insulating gloves.
• Note that positions indicated below are dangerous even after the power is turned off be-
cause an electric charge remains and a high voltage continues to exist there.
Before starting any repair work, perform discharge by connecting a discharge resistor (5k-
ohms/10W) between terminals at following positions. The time required for discharging is
about 30 seconds.
1. C141 on MAIN (1) P.C.B..
2. C142 on MAIN (1) P.C.B..
A, G, L models
A, G, L models
IMPEDANCE SELECTOR
LOW/HIGH
CB106
POWER TRANSFORMER
J
• Semiconductor Location
Ref no. Location Ref no. Location
D101 B4 Q112
C3
D102 B3 Q113 B4
D103 C4 Q114
B3
D104 C3 Q115 B4
D105 C4 Q116 B3
D106 C3 Q117
D5
D107 F4 Q118 D3
D108 F3 Q119A D5
D109 B6 Q119C D5
D111 G5 Q120A D3
D112 Q120C
G3 D3
D116 G5 Q121 B5
D117 G5 Q121A D5
D118 Q121C
G6 E5
D119 G6 Q122A C3
D120 H6 Q122C
E3
D121 B6 Q123A C5
D122 B6 Q123C E5
D262 Q124A
B5 D3
IC101 D2 Q124C E3
IC102 Q125
D6 C4
Q101 B5 Q126 C4
Q103 B4 Q127 F5
Q104 Q128
B4 F3
Q105 B4 Q129 F5
Q106 B4 Q130 B6
Q107 B4 Q131 B6
Q108 B3 Q132 H5
Q109 Q133
B4 G3
Q110 B3 Q255 G3
Q111 C4 Q256 H5