Yamaha A-S3000 Service Manual page 58

A B
A-S3000
1
MAIN (3)
(Side A)
2
3
4
5
MAIN (2)
(+B3, -B3, +B4, -B4)
6
FRONT (16)
(W415, W416)
7
58
C D
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 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.
C317–C320 on MAIN (3) P.C.B.
5 k-ohms
10 W
5 k-ohms
10 W
-PB
AGND
MAIN (2)
(W201) AGND
+PB
BL
W312
RE
IC303
WH
W306 RE
WH
IC304
W314 BL GR
BE
RE
W308 RE
POWER TRANSFORMER
Capacitor
• Semiconductor Location
Ref no. Location
D301
D302
D303
D304
D305
D306
E F G
安全対策
・ この製品の内部には高電圧部分があり危険です。修理の際は、絶縁性の手袋を使用するなどの安全対策を行ってください。
・ 下記のコンデンサには電源を OFF にした後も電荷が残り、高電圧が維持されており危険です。修理作業前に放電用抵抗
5 k-ohms
MAIN (2) 5 k-ohms
(W208)
10 W
CB308
CB305
IC301
IC302
PRV
FUNCTION (2)
+5S
(W51)
MG
PSVA2
PSVA1
FUNCTION (1)
POWER TRANSFORMER
(W501)
Ref no. Location Ref no. Location Ref no. Location
H4 D307 G5 D307 G5 D333 D4
H5 D308 G5 D308 G5 D334 C4
G4 D303 G4 D319 G5 D335 C5
G4 D304 G4 D330 D5 IC301 G4
E3 D305 E3 D331 D5 IC302 G5
D306 F3 D332 D4 IC303 D4
F3
H I
（5 k Ω /10 W）を下記の各コンデンサの端子間に接続して放電してください。放電所用時間は各々約 30 秒間です。
MAIN（3）P.C.B. の C317 C320
10 W
POWER TRANSFORMER
POWER TRANSFORMER
-PB
MAIN (1)
AGND
(W101)
AGND
+PB
W311
BL
RE
WH W306
RE
WH
GR
BL W313
BE
RE
W307
RE
Capacitor
FRONT (15)
(W413, W114)
Ref no. Location
IC304 D5
Q304 F5
J
FUNCTION (2)
(W52)
MAIN (1)
(+B1, -B1, +B2, -B2)