Main P.c.b. - Yamaha AS2000BL Service Manual

A B
A-S2000
1
MAIN (3) P.C.B.
(Side A)
2
3
POWER TRANSFORMER
4
POWER TRANSFORMER
5
HP GND
HP GND
HP GND
MAIN (2)
(CB52)
6
7
50
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 positions 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, 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. C308 on MAIN (3) P.C.B..
2. C309 on MAIN (3) P.C.B..
3. C335 on MAIN (3) P.C.B..
4. C336 on MAIN (3) P.C.B..
FUNCTION (3)
(CB25)
W317
W304D
-B3
BL
W304C
BE
+B3
W304A
CB26
-B4
BR
CB21
W304B
GY
+B4
5 k-ohms
+PB 10 W
AGND
AGND
-PB
MAIN (2)
(CB72)
E F G
5 k-ohms 5 k-ohms
10 W 10 W
IC300
IC302
IC303
5 k-ohms
10 W
MAIN (1)
H I
W303C
+B1
BE
POWER TRANSFORMER
W303D
BL
-B1
CB24
W303B
+B2
GY
CB22
W303A
BR
-B2
POWER TRANSFORMER
• Semiconductor Location
IC301
PRV
+PB
+33V
AGND
AGND
AGND
-33V
-PB
60GND
(CB52)
FRONT (11)
(CB34)
J
Ref no. Location Ref no. Location
D300 H3 D332 D4
D301 H4 D333 D3
D302 G3 D334 D3
D303 G3 D335 D5
D304 D5 D336 D4
D305 H5 D337 G3
D307 G4 D338 G3
D308 G4 D339 G4
D311 G3 D340 G4
D312 G3 D341 D3
D313 G4 D342 D3
D314 G4 D343 D4
D315 F3 D344 D4
D325 D3 IC300 F3
D326 D3 IC301 G3
D327 D4 IC302 F4
D328 D4 IC303 F5
D331 D4 Q303 F3