Yamaha A-S701 Service Manual page 48

A B
A-S701
1 MAIN (1)
(Side A)
2
3
4
5
A, B, G, L models
6
7
48
C D
PREOUT_L
AGND
PREOUT_R
+7V
-7V
AGND
W104
CB104
POWER
TRANSFORMER
E F
MAIN (5)
(Side A)
FUNCTION (1)
to HEATSINK R temperature
(W405)
VCC
FUNCTION (1)
(W505) GND
OUT
PREMT
SWMT
MG
+5S
POW_MGT
THM
THM
SPBRY
SPARY
PRIY
PRI
PRD
# # #
Q122C Q124C Q124A
5 k-ohms
10 W
5 k-ohms
10 W
Q121C Q123C Q123A
# # #
Note: Those parts marked with "#" are not included in the P.C.B. ass'y.
MAIN (4)
(Side A)
CB106
OUT
GND
VCC
Safety measures
MAIN (2) to HEATSINK
• Some internal parts in this product contain high voltages and are dangerous. Be sure to take safety measures during servicing, such
(CB13) L temperature
as wearing insulating gloves.
• Note that the capacitors indicated below are dangerous even after the power is turned off because an electric charge remains and a
high voltage continues to exist there. Before starting any repair work, connect a discharging resistor (5 k-ohms/10 W) to the terminals
of each capacitor indicated below to discharge electricity. The time required for discharging is about 30 seconds per each.
C134, C135 on MAIN (1) P.C.B.
G H I
B, G models
CB105
#
CB101
Q122A
Q121A
#
J
FUNCTION (2)
(W401)
FUNCTION (2)
(W402)
• Semiconductor Location
Ref no. Location
D111 D6
IC101 F6
IC102 G2
Q137 D5
Q129 D6
Q127 D6
Q139 F3
Q119 F4
Q138 G3
Q118 G3
Q120 G4
Q117 G5
Q115 H3
Q116 H4
Q113 H4
Q114 H4
IC101 F6
IC102 G2