Yamaha A-s300 Service Manual

IC1
OPERATION (1) P.C.B.
(Side B)
5
4 1
3
R model U, C, T, A, B, G, L, J models
ABCDE FGH I J
1
2
3
4
5
6
7A-S500/A-S300
41
• Semiconductor Location
Ref no. Location
D1 F3
D2 F3
D3 D6
D4 G3
D5 G3
D6 G3
D7 G3
D8 G3
D9 G4
D10 G5
D11 G4
D12 G3
D15 F3
IC1 F3
Q1 G2
Q2 E3
Q3 G3
Q9 G3
A-S500
A-S300 

CB808
W803
CB804
W804
W801
W808
CB802
W807
CB803
W809A W809B
PURE DIRECT
OPERATION (2) P.C.B.
(Side A)
MGMPSWRECKEY1+5SREMMPLED+5M
AGNDMIRAGND
MIL
+5SMGCD_SWPD_SW
PREMT+5S
KEY1
REC
FL_N_RST
FL_N_CE
ZPLED
MPSW
RM2-
RM1-
+5M
MG
KEY0
MPLED
FL_MOSI
FL_SCK
KEY1_N_INT
REM
RM2+
RM1+CLED+MGPLED+
AGND
TOL
TOR +15
VOL
AGND VOR-15
-15+15POR
AGND
POL
-15+15VOLAGNDVORAGNDAGNDCDR+OCDR-OAGNDAGNDCDL+OCDL-O
OPERATION (6)
(W801)
OPERATION (5)
(W802)
OPERATION (9)
(CB852)
FUNCTION (1)(CB504)
OPERATION (1)
(W1A)(W1B)...

IC802
OPERATION (2) P.C.B.
(Side B)
8
1 5
4
ABCDE FGH I J
1
2
3
4
5
6
7A-S500/A-S300
43
• Semiconductor Location
Ref no. Location
IC802 E4
Q801 G3
Q802 G3
A-S500
A-S300 

CB902 CB901CB951
W801
W805AW806A
SW804
SW803
SW802
W802
OPERATION (2)
(CB804)
L/R -/+ -/+
BALANCE
INPUT PHONODOCKTUNERCD
LINE 1
LINE 2
LINE 3
PURE DIRECT
indicatorTREBLE BASSFLAT/-30dB
REC OUT SPEAKERSLOUDNESS
A-S500
OPERATION (3) P.C.B.
(Side A)
OPERATION (5) P.C.B.
(Side A)
OPERATION (4) P.C.B.
(Side A)
OPERATION (6) P.C.B.
(Side A)
LOLLOR
VOL
AGNDVORPHONO_LEDDOCK_LEDTUNER_LED
CD_LEDLINE1_LEDLINE2_LEDLINE3_LED
ISAISB+5SMG
+15TOR
-15VORAGND
TOL
VOL
VOR
AGNDVOL
LORLOL
+5M
MPLED
REM
+5S
KEY1
REC
MPSW
MG...

IC901
OPERATION (3) P.C.B.
(Side B)
OPERATION (5) P.C.B.
(Side B)
OPERATION (4) P.C.B.
(Side B)
OPERATION (6) P.C.B.
(Side B)
4
51
8
A-S500
ABCDE FGH I J
1
2
3
4
5
6
7A-S500/A-S300
45
• Semiconductor Location
Ref no. Location
IC901 D2
Q804 C6
Q805 C5
Q806 C5
Q807 C5
Q808 C5
Q809 D5
Q810 D6
A-S500
A-S300 

CB9CB8
CB10
SW1
JK701
CB706
W806B
SW805W805B
CB852
CB856
CB851 CB855IC851
CB853CB854
RE
YE
OR
PU
CDL-O (For service)
(For service)CDL+OAGNDAGNDCDR-OCDR+OAGNDAGND
VOR
AGND
VOL
+15
-15
POWER TRANSFORMER
PHONES
OPERATION (10) P.C.B.
(Side A)
OPERATION (7) P.C.B.
(Side A)
R model
OPERATION (8) P.C.B.
(Side A)
OPERATION (11) P.C.B.
(Side A)
OPERATION (9) P.C.B.
(Side A)
VOLUME
M+
HPR
HPE
HPL
-15
+15
VOL
AGND
VOR
AGND
AGND
CDR+O
CDR-O
AGND
AGND
CDL+O
CDL-O
LEDMPSW+5M
(Power)POWER
indicator
MG...

OPERATION (10) P.C.B.
(Side B)
OPERATION (7) P.C.B.
(Side B)
R model
OPERATION (8) P.C.B.
(Side B)
OPERATION (11) P.C.B.
(Side B)
OPERATION (9) P.C.B.
(Side B)
ABCDE FGH I J
1
2
3
4
5
6
7A-S500/A-S300
47
• Semiconductor Location
Ref no. Location
D821 F6
D822 E6
D851 I3
D852 I3
D855 I5
Q803 F6
A-S500
A-S300 

IC102
CB107
W105 CB108W103 W102SW102
CB101
SW101
CB104 W104
IC101 CB106
Q124A
Q124C
Q123A
Q123C
POWER TRANSFORMER
+ON/OFF OUT
POWER
MANAGEMENT
HIGH/LOW
IMPEDANCE
SELECTOR
SUB
WOOFER
- + -
R L
A/B
SPEAKERS
A-S300
MAIN (1) P.C.B.
(Side A)
MAIN (4) P.C.B.
(Side A)
MAIN (3) P.C.B.
(Side A)
A-S300
T, A, B, G, L models
PREOUT_L
AGND
PREOUT_R
+15V
-15V
AGND
HPR
E
R
E
L
EHPLPRV-15UNREG+15UNREG-VP_UNREGE+VP_UNREG
E
ACL
ACL
ACH
ACH
5 k-ohms
10  W5 k-ohms
10  W
PREMT
SWMT
MG
+5S
POW_MGT
THM
THM
SPBRY
SPARY
HPRY...

IC103
MAIN (1) P.C.B.
(Side B)
MAIN (4) P.C.B.
(Side B)
MAIN (3) P.C.B.
(Side B)
8
15
4
ABCDE FGH I J
1
2
3
4
5
6
7A-S500/A-S300
49
• Semiconductor Location
Ref no. Location
D109 G5
D110 G3
D112 G6
D113 H3
D114 G6
D117 H5
D118 G6
D119 H5
D120 F5
D121 G3
IC103 H3
Q125 G3
Q126 G6
Q128 G6
Q132 H3
Q135 H3
Q136 G6
Q140 G3
Q141 G5
A-S500
A-S300 

CB15 CB12W10
CB13
CB14
CB5CB8
AC OUTLETS
MAIN (2) P.C.B.
(Side A)
MAIN (5) P.C.B.
(Side A)
A-S300 (J model)
MAIN (6) P.C.B.
(Side A)
TRIGTRIGMG
7.0S
PurpleWhitePurpleNC
Gray
GrayHPREHPL
HPREHPLPRV-15UNREG+15UNREG-VP_UNREGE+VP_UNREG
+15V
AGND_BTN
-15V
PRV
FUNCTION (3)(W602)OPERATION (1)(CB16)
MAIN (1)
(W104)
POWER TRANSFORMER
OPERATION (8)
(CB706)
FUNCTION (1)(W502)
AC IN
ABCDE FGH I J
1
2
3
4
5
6
7
50A-S500/A-S300
• Semiconductor Location
Ref no. Location
D14 G5
Q4 H5
Q5 H5
Q6 H5
Q7 H5
Circuit No. U, C,...