Kenwood KRC-2902YA User manual

©2002-1 PRINTED IN JAPAN
B51-7882-00 (N)1089
CASSETTE RECEIVER
KRC-2902YA/G
SERVICE MANUAL
45Wx4
HIGH POWER
KRC-2902
LOUD
PWR
OFF
AMEAUTO
CLK
SRC
AUD
T. CALL
MENU
WIDE BAND
REW
PR FF OG
Lever
(D10-3031-04)x2
Plastic cabinet assy
(A02-1486-13)
Mounting hardware assy
(J21-9491-13)
DC cord
(E30-4790-05)
Antenna adaptor
(T90-0523-05)
Escutcheon
(B07-2124-02)
Knob (ATT)
(K25-1388-03)
Cassette lid
(A53-1638-13) Panel assy (A64-2520-02)

KRC-2902YA/G 2
BLOCK DIAGRAM
IC1
KEY
PAN 5V
MUTE
B.U. DET. B.U.
ACC
POWER IC
EQ. AMP.
CH ISO AMP
NC/MPX/
E-VOL.
FRONT Lch
FRONT Rch
REAR Lch
REAR Rch
J2
LCD DRIVER
LCD
MAIN
TAPE MECHA.
IC5
IC2 IC4, Q151
IC3,Q150
SP OUT
PAN IN SW ACC DET.
P-CONT.
J2
IC1
FM+B
Q200,201
AM+B
Q202,203
AM BPF
FM BPF
Q320
Q50
Q350-353
Q53
SW 5V
Q54-57
COM+B
Q58-61
ILLUMI.
B.U. 5V
Q51,52
SYSTEM u-COM
RST SW
Q301
MOTOR SW
RST
Q260,261
ED1 Q1
FM ANT
AM ANT
RF GND
FM+B
AM+B
OSC GND
OSC GND
OSC GND
VT
PLL +B
IFC OUT
SDA
SCL
DIG GND
IF1+B
IF1 GND
S-METER
IF2 GND
SD
FM+B
SW5V
ACC DET
B.U. DET
SCL
MUTE
SDA
P CON
PANEL HOLD L CLK L DATA S L DATA L FWD/REV MOTOR
Rch
COM
Lch
MP IN
AM
MPX
OUT RR
OUT LR
OUT RF
LEVEL
SCL
SDA
OUT LF
STBY
MUTE
Rch
Lch
T-MUTE
FWD
REV
B.U.5V
B.U.
8V B.U.
S MUTE
4
65
B.U.5V
AM+B
VDD 5V
PACK IN L RES
ANT CON
BEEP
SVR
AMP. STBY
SVR
AC GND (BEEP)
Rch Lch
8V
RF GND
OSC GND
IF2 +B
AUDIO OUT
8V
S-METER
SD
PLL CLK
PLL DATA
PLAY
HEAD
R
L
55.6mV
B.U.5V
SW5V
8V
B.U.5V
AM: 170mV
FM: 400mV
TAPE
PACK IN
(FF/REW)
AMP. MUTE
FF/REW
B.U.5V
ILLUMI.
(X16- )
(X14- )
M
A1
5V
D200
P-CONT.
/ANT-CONT.

KRC-2902YA/G
3
● SYNTHESIZER UNIT (X14-6872-73)
COMPONENTS DESCRIPTION
Ref.No. Function Operation
IC1 SYSTEM µ-COM Controls the unit.
IC2 E -VOLUME Controls the volume and selects source.
IC3 M UTE LOGIC Controls the mute output.
IC4 POWER AMPLIFIER For the speaker output.
IC5 EQUALIZER AMPLIFIER For the cassette tape's signal.
IC6 RESET Resets the power.
Q49 A CC DETECTION SW Outputs "H" during the ACC off.
Q50 BACK-UP DETECTION SW Outputs "H" when the back-up voltage is under 9.2V.
Q51,52 BACK-UP 5V DRIVER Works when back-up current exists.
Q53 P.ON 5V SW Works during the power on.
Q54,55 8V SW Works during the power on.
Q56,57 8V DRIVER Works during the power on.
Q58,59 ILLUMI +B SW Works during the power on.
Q60,61 ILLUMI +B DRIVER Works during the power on.
Q150 E-VOL MUTE SW
Works when the back-up current is detected or the changer mute works or system
µ -com mute works.
Q151 SVR FORCED DISCHARGE SW Works when the amplifier mute works.
Q201 FM +B SW Works during FM mode.
Q203 AM +B SW Works during AM mode.
Q260 MOTOR +B SW Works during the tape mode.
Q261 MOTOR +B DRIVER Works when Q206 works.
Q301 CD-CH RESET SW Works when the power is reset and the reset SW works.
Q320 PANEL 5V SW Works when the back-up current exists and the panel is attached on the unit.
Q350 P.CON DRIVER SW Does not work during the power off and the ALL OFF.
Q351 P.CON PROTECTION SW Works when the P.CON is short-circuited on the GND.
Q352
P.CON PROTECTION INHIBIT SW Inhibits the protection SW in a moment during the P.CON on.
Q353 P.CON DRIVER SW Does not work during the power off and the ALL OFF.

KRC-2902YA/G
4
● µ-COM (IC1 : X14-)
Pin No. Pin name I/O Description Processing Operation
1 PANEL I Panel detection. "L" : Panel exists.
2 L CE O LCD driver chip enable. -
3 L RES O LCD driver reset. -
4 AVSS - GND. -
5 R DATA I RDS data. -
6 R QUAL I RDS receiving. -
7 AVREF 1 - Reference voltage. -
8 I C2 SEL 1 I Selector. "L" : Normally.
9 I C2 SEL 0 I Selector. "L" : Normally.
10 - - - -
11 L DATA L I LCD driver communication data. -
12 L DATA S O LCD driver communication data. -
13 L CLK O LCD driver communication clock. -
14,15 - - - -
16 DATA C I Changer communication data. -
17 DATA H O Changer communication data. -
18 CH CLK I Changer communication clock. -
19-26 - - - -
27 MOTOR O Cassette tape motor SW. -
28 FF/REW I Cassette tape FF/REW detection. "L" : FF or REW works.
29-31 - - - -
32 SD I Signal detection. "H":Signal exists. "L" : Signal does not exist.
33 VSS 1 - GND. -
34 - - - -
35 PLL CLK O Front-end communication clock. -
36 PLL DATA I/O Front-end communication data. -
37 AM +A O AM power supply SW. -
38 FM +B O FM power supply SW. -
39 IC2 DATA I/O E-volume communication data. -
40 IC2 CLK O E-volume communication clock. -
41 AFC O FM noise detection /Time constant SW. -
42 MUTE O Mute control. -
43 AMP MUTE O Power amplifier mute. -
44 - - - -
45 CH CNT O Changer control. -
46 REQ H O Changer request. -
47 - - - -
48 SVR O SVR control. -
MICROCOMPUTER'S TERMINAL DESCRIPTION

KRC-2902YA/G
5
Pin No. Pin name I/O Description Processing Operation
49 AMP STBY O Power amplifier stand-by. -
50 BEEP O Buzzer signal output. -
51,52 - - - -
53 P.CONT O Power control SW. -
54 ACC DET I ACC detection. -
55 B.U.DET I Back-up detection. -
56 P.ON O Power SW. -
57 ILLUMI O Illumination SW. -
58 FWD/REV I Cassette mechanism FWD/REV detection. -
59 - - - -
60 RESET I System reset signal input. -
61 SEL 1 I Destination SW. -
62 R CLK I RDS clock. -
63 REQ C I Changer request. -
64 PACK IN I Cassette tape pack-in detection. -
65 KEY-REQ I Key signal input detection. -
66 SEL 0 I Destination SW. -
67 VSS 0 - GND. -
68 VDD 1 - 5V power supply. -
69 X2 - Main system clock. -
70 X1 I Main system clock. -
71 IC - GND. -
72 - - - -
73 XT1 - 5V power supply. -
74 VDD 0 - 5V power supply. -
75 AVREF 0 I A/D converter reference voltage. -
76 S METER I S-meter detection. "H" : S-meter exists. "L" : S-meter does not exist.
77 PHONE I - Navigation mute : 2.5V or more.
Telephone mute : 1V or less.
78 NOISE I FM noise detection. -
79 AV CONT O A/D converter reference voltage. -
80 - - - -
MICROCOMPUTER'S TERMINAL DESCRIPTION

KRC-2902YA/G
6
TEST MODE / ADJUSTMENT
(2-LINE TAPE)
B
A
B
A
(FWD)
(RVS)
HEIGHT
(FWD)
HEIGHT/AZIMUTH
(FWD) HEIGHT/AZIMUTH
(RVS)
TAPE SPEED
HEIGHT
(RVS)
F''
F
R
R
1. How to enter the test mode
• Reset the unit while holding the "FM" key and preset "6" key.
• All indication segments go ON at the beginning of the test
mode.
2. How to release the test mode
• Simply reset the unit.
• (NOTE) The test mode is not canceled by ACC OFF, power
OFF, momentary power down or the panel off.
3. Audio adjustment
• Set the volume level to -10dB (which is shown as "30" on the
display).
• Loudness OFF.
• The BASS/TREBLE and BALANCE/FADER can be set to
the full-boost/full-cut and full-front/full-rear each by pressing
the "Track UP" / "Track DOWN" keys.
• Sound coordination doesn't appear for the feed.
TEST MODE
ADJUSTMENT
Head Angle Adjustment
Head height alignment procedure
• During FWD transport adjust screws Fand F' so that line A
of 2-LINE TAPE passes trough the center of the head shield
plate (core center area)
• During RVS transport adjust screws Rand R' so that line B
of 2-LINE TAPE passes trough the center of the head shield
plate core (center area)
• After the alignment above, reverse the transport direction
and check the FWD alignment again. If it is deviated,
perform alignment again. (Tape used : SCC-1659,
manufactured by A-BEX)

ABCDEFGHIJ
1
2
3
4
5
6
7
78
PC BOARD (FOIL SIDE VIEW) (COMPONENT SIDE VIEW) (FOIL SIDE VIEW)
Refer to the schematic diagram for the values of resistors and capacitors.
4.3320MHz
W24
W64
W76
W78
R200
R202
W36
R55
W73
W69
W12
W99
R67
W58
W104
C4
R350 R370
W67
W57
W70
C209
L10
W66
W68
W4
W6
W72
W71
W7
W85
W80
W39
W42
W45
W48
W50
W101
W102
W2
W200
R51
R65
R351
R353
R66
X1
C50
C17 C18
C160
C152
C55
W15
C15
C16
C161
C350
C352
C503
C162
C500
C450
C451
C150
C159
C56
C58
C53
C57
W97
W98
W103 W53 W43
W51 W28
W10
X2
W17
R501 W3
R502
R500
R261
L5
R260
L4
C402
C400
C401
W54
W47
W95
W93
W89
R119
W13
W61
W62
W14
C9 C250
C10
W8
W9
W33
W23
W27
W30
W32 W37
W26
W55
W56
R263
R262
W22
W77
W63
W65
W21
R252
W105
W52
W100
W94
W96
W92
W91
W90
W87
W59
W60
W20
W25
W29
W31
W35
W19
W11
W82
W79
W83
W40
W38
W41
W84
W81
C3
W34
W18
W49
W46
W44
R120
W88
W74
W75
4.19MHz
TP
5V
DG
S-MTR
PDA
PCK
2DA
CCK
DTH
DTC
CMP
2CK
L1
RES
L8 L7
R100
L12
L6
L3
W5
R107
1
6
8
1
1
5
8
16
1
9
1
2
25
24
1576109
2 3 4 8 12 11 13
LR
1
24
BEBE
EB
BE
BE
111
212
BE BE
A1
Q60
Q56
D370 D410
D50
D405
D371
D352
Q51
Q350
D380
D401
D400
D56
D52
D51
D55
D54
D408
D409
D350
D351
D53
Q261
Q201
Q203
D404
D200
D260
P1
IC5
D261
J1
J5
J4
J2
J3
IC4
D150
D152
D151
WH1
D100
CN1
X14-6872-73 (J74-1319-02)
W170
C251
R156
R15
W158
R14
R62
W159
R57
R59
W157
R60
C52
C163
R161
R159
R162
R16 R13
W174
R381
C380
R61
R251
R151
C214
R503
C600 C601
W171
R125
R123
C13
C14
R58
R52
R54
R106
R112
C164
R352
C154
C153
C351
TH1
R504
R155
R154
R153
R322
R401
R400
R380
R408 R409
R407
R406
R412
R410
R411
R303
R302
R304 R306
R305
R403
R301
R402
C504
C54
C502
C505
R63 R64
W162
C501
R1
C1
R201
R203
R150
W153
C452
C202
C204
R455
R453
R454
R451
R450
R452
R205
R141
R2 C2
C5
R382
C6
C157
R111
R113
R404
R103
R108
C151
C156 C155
R160
R206
R207
C158
C506
R8
C8
R4
R6
R7
C7
R5
R133
R323
R110
R158
C101
C102 R105
C103
W161
W160
R48
R320
R321
R140
W173
W154
R124 R122
R118
R152
R121
R117
R157
R405
R143
R104
W169
W168
W167
R3 R250
W165
R49
R413
W156
R142
W166
W164
R101
R102
C104 W163
114
1528
814
71
41
13
45
60
1
20
80
61
21
40
18
16 9
BE
BEBE
BE
BE BE BE
BE
BE
BE
BE BE
BE
BE BE
BE
BE
BE
BE
BE
BE
BE
BE
BE
BE
Q61
IC1
Q52
Q59
Q58 Q57
Q153
Q151
Q150
Q55
Q49
Q54
Q53
Q50
Q500
Q502
Q501
Q353
Q301
Q320
Q352
Q351
IC6
IC7
Q451
Q450
Q260
IC3
IC2
Q503
PL1 PL2
FM
AM
AUD
RST654321ATT
VOL
SRC
TI
1 54
CLK
D15
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
D11
D12
D13
D14
X16-1512-7x (J74-1300-02) X16-1512-7x (J74-1300-02)
C5
C2
C3
C4
R2 R3
R4
R5
R6
R7
R8
R9
R21
R10
R11
R12R13
R14
R15
R17
R18
C1
1
2441
64 65 80
40 25
11
12
2
1
BEQ1
IC1
D17
J1
Ref. No address
IC1 3J
Q1 4J
X16-1512-7x
Ref. No
address
Ref. No
address
IC1
5C
Q59
4A
IC2
4E
Q60
3A
IC3
4D
Q61
3A
IC4
2D
Q150
4D
IC5
4B
Q151
3D
IC6
5C
Q201
4E
Q49
4C
Q203
4E
Q51
4B
Q261
6E
Q50
4B
Q260
5E
Q52
4B
Q301
5C
Q53
4B
Q320
6B
Q54
3B
Q350
3C
Q55
3B
Q351
4C
Q56
2A
Q352
4C
Q57
3A
Q353
4C
Q58
4A
X14-6872-73
SYNTHESIZER UNIT SWITCH UNIT

ABCDEFGHIJ
1
2
3
4
5
6
7
AM+B
19
23
20
21
22
AUDIO OUT
SD
S-METER
IF1+B
14
17
18 VDD 5V
IF2+B
15
16
SDA
SCL
DIG GND
10
11
12
13
OSC GND
VT
PLL+B
IFC OUT
7
8
9
OSC GND
OSC GND
OSC GND
FM ANT
3
4
5
6
AM ANT
RF GND
FM+B
1
2RF GND
16 15 14 13 12 11 10 9
876543 2 1
FL+ RL+
FL-
RL-
FR-
RR- FR+ RR+
P-ANT
P-CON
ACC
B.U
GND
19
23
17
21
9
3 7 5
L1
C50 3300u16
+
0.01
3.3K 1/2W
33K
R52
10K
R54
R370 4.7K
R350 4.7K
R351 1K
R352
3.3u25
C350
+
22K
C351
0.1u50
C352
+
1K
0.068
100u10
C159
+
+
C160
10u16
R152 1K
R151 4.7K
91K
R153
180K
C162 1u50
+
R157 100
R158 33K
R155 430
R156
23
24
25 26
0.01
C151
47u10
C150
+
L3 4.7uH
0.1
C158 R150 4.7K
0.1
C155
C153 0.015
C154 0.22
0.033
150P
C157
C156
0.22 0.22
24 IF1 GND
IF2 GND
0.01
C202
0.01
C204
22K
R203
22K
R201
1K
R202
1K
R200
R205
150
35
36
4.7uH
76
32
C209 47u10
+
1
2
3
4
5
0.047
C251 10K
R251
1500P
C2
1500P
C1
22K
R1 22K
R2
12 11 10 987654321
PAN 5W
L DATA S
L CLK
L CE
L DATA L
u GND
PAN5V
RESET
ILL GND
ILL +B
ESD GND
R322 2.2K
R301 470 R302 470
R303 1K R304 1K
27K 47K
R320R321
100u16
C57
+
R62
100u10
C58
+
1K
R64
1K
R63
R65
2.2 1/2W
R66
2.2 1/2W
R207 2.7K R206 4.7K
3
4
48
49
43
13 12
2
11
60
55
C56
100u6.35.6K
R61
+
47K
R60
10u10
R58
22K
100
R59
C55
+
C54
0.01
100u16
+
1K
R67
50
GND
7
R162 47K
6
5
4
3
C164
0.01
2
1
9
8
11
10
12
13
VDD 14
+
0.022
4
C7
120K
R7
100u10 100
+
100P
C5
C9
R5 6.8K
R3
L IN 8
L NF
L OUT
7 6
C3
47u6.3
3
10
R250
120K
R8
C250
100u10
R6 6.8K
+
C8
0.022
C10
100u10 R4
100
GND
VCC
R OUT
5
4
100P
C6
R NF
3 2
+
+
C4
47u6.3
R IN 1
40
39
C53
37
38
F1 (10A)
R159 100K
28 27 26 25 24 23 22 21 20 18 17 16 15
AC OUT L
AC OUT R
OUT LF
OUT RF
OUT LR
OUT RR
VDD
GND
SDA
S MUTE
QUAL
MUX R
MUX L
1
2 3
4
5 6 7 8
9
10
11
12 13
14
VREF CREF TAPE L TAPE R CDR CDGND CDL PH- PH+ AM MPX LEVEL MP IN MP OUT
1
C14
C13
L4
52mH
56 55 54 53 52 51 50 49 48 47 46 45 44 43 42
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
1
2 3
4
5 6 7 8
9
10
11
12 13
14
15 16
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
P.O N
B.U.DET
ACC DET
P. CONT
BEEP
AMP STBY
SVR
REQ H
CH CON
AMP MUTE
MUTE
AFC
PLL DATA
PLL CLK
VSS 1
SD
FF/REW
MOTOR
PANEL L CE L RES AVSS R DATA R QUAL IC2 SEL 0 L DATA L L DATA S DATA C
SEL 1
R CLK
PACK IN
VDD 1
X2
X1
IC
XT1
VDD 0
S METER
R306 1K
2
2
TH1
P1
10
R323
1/2W
1/2W
Q151
Q320
10K
Q54,55
Q150
16
DATA H
17
CH CLK
18
19
20
IC2 SEL 1 AVREF 1 L CLK
11
12 13
28
27
4.7K
R117
R119 2.2K
R120 1K
R121 10K
1K
1K
R123 10K
R122
R124
IC2 CLK
IC2 DATA
FM+B
AM+B
36
35
39
37
38
40
32
41
REQ C
KEY-REQ
SEL 0
VSS 0
AVREFO
PHONE
NOISE
AV CONT
R106
2.2K
47K
R105
6.8K
X1
C102
15P
15P
C103
3 2
1
57 58 59 60
10
R100
0.022
C104
RESET
FWD/REV
ILLUMI
55
R55
47K
47K
R57
C52
54
54
R353
Q351
53
48 50
49
43
T-MUTE
R380
10K
0.01
C380
22K
R381
R104 47K
R140 47K
2.2K
R142 47K
R110 100K
R113
2.2K
R102
L RES R305 1K 3
57
57
R49
100K
22K
R48
53
21
3
1
11
5 7
9
13 15 17
19
23 25
TAB RR+ RR- FR- FR+ FRI
GND
RLI RL+ RL- FL- FL+ CD
GND 2
4
STBY 6
VCC 8
GND 10
SVR 12
RRI 14
FLI 16
AC GND 18
GND 20
VCC 22
MUTE 24
GND
4.7K
R14
0.22u50
C16
750
4.7K
0.22u50
C18 R16
4.7K
0.22u50
C15 R13
1u50
+
0.22u50 4.7K
R15
C17
17
19
23
21
24
25
23 26
R154 C161
19
SCL
1u50
C152
+
L6
4.7uH
4.7uH
L7
L10
0.01
C214
58
60
RL-
BU
YEL
9
TEL MUTE
BRN
12
11
10
VIOL/BLK
GRN/BLK
RR+
RR-
RL-
VIOL
15
13
14
RL+
GRN
16
1357
RR+
RL+
FL+ FL-
FR-
RR-
FR+
2
2
68
57
4
13
68
GND
4
ACC
P-CON
B
A
BLK 1
ANT. CON
P. CON
BLU/WHT
BLU/WHT
RED
4
2
3
GRY/BLK
WHT/BLK
GRY
7
6
5
FR-
FR+
FL-
WHT 8FL+
R261
R262 47K
GND 1
PACK IN 2
1/2W
1K
R260
10K
47K
R263
GND 5
MOT 3
MOT 4
T.MUTE 6 28
27
+B
GND
IC4
Q58,59
Q60,61
Q301
Q261
Q350,353
Q352
Q51,52
Q56,57
76
3 5 7
9
47K
R252
R382 47K
R51
47K
R133
4.19MHz
100K R111
R112
W200
L8
4.7uH
1
2
34
5
C101
0.01
58
+B
+B
+B
+B
+B
+B
+B
+B
+B+B
+B
+B
+B
+B+B
+B+B
+B+B
+B
+B+B+B
+8V +8V
+8V +8V
+5V
+8V+8V+8V
+8V +8V +8V
+5V
+5V
+5V
+5V +5V
+5V
+5V
+5V
+5V
+5V
+8V+8V
+8V
+5V
+5V+5V+5V
+5V
P5V
P5V
P5V
P5V P5V P5V P5V P5V
+5V
IC3
IC5
KRC-2902YA/G (1/2)
SYNTHESIZER UNIT (X14-6872-73)
IC4
IC2
IC1
A
IC6
(E30-4790-05)
DC1
47K
47K
22K
22K
22K
47K
10K
47K
47K
47K
10K
22K
22K
47K
22K
47K
22K
22K
10K
47K
A1
J2
D50
D261
D52 D51
Q50
D351
D370
ANT-CON.
Q350
Q351
D352
Q353
Q352 Q151
D150
D152
D151
Q150
Q201
D200
Q203
ANT
J1
CN1
J3
Q320
Q55
Q54
D55
Q56
Q57
SW
Q301
Q53
Q52
Q51
D53
D54
Q58
Q60
Q61
Q59
D56
8V
IC1 :
IC2 : TDA7400D
IC3 : HD74HC27FP
UPD780058GC425
IC4 : TDA7386
IC5 : LA3161
Q49,50,52,57,61 : 2SC2412K or
2SD601A
Q51,261 : 2SB1443
Q53 : 2SA1036K
Q54,58 : DTC144EK or
KRC104S
UN2213 or
Q55,59,352 : DTA124EK or
UN2112 or
Q56,60 : 2SA2057 or
2SB1548(P) or
Q201,203,350 : 2SB1277(Q,R)
Q301 : DTA144EK or
UN2113
Q320,351 : 2SA1037K
D50 : 1N5393G-M6 or
S2V20∗A
D51 : MA4068(N)-M or
HZS7A3L
D52,200 : MA4051(N)-M
D53,260,261,351,370,371
:AM01Z or
ERA15-01
D54 : MA4056(N)-M
D55 : MA4091(N)-M
D56 : MA4110-L
D100,150-152,352
: 1SS133
J1
X16-
2/2
D371
Q150 UN2212 or DTC124EK or:
Q151,260,353 UN2214 or
KRA103S
2SB1655(E,F) or
2SB1565(E,F)
KRC103S
KRC107S
DTC114YK or:
ILLUMI
+B SW
ILLUMI
+B DRIVER
DRIVER SW
P.CON PROTECTION SW
P.ON
5V SW
SYSTEM u-COM
DISCHARGE SW
PANEL 5V
SW
8V
DRIVER
EQUALIZER
AMPLIFIER
E-VOLUME
FM+B
SW
AM+B
SW
TUNER
E-VOL
MUTE SW
Q49
P-CON.
P.CON
SVR FORCED
DETECTION
ACC
D380
D100
PST9135NRIC6 :
MOTOR
+B SW
Q260
MOTOR+B
DRIVER
D260
WH1
Q261
MUTE LOGIC
POWER
ANPLIFIER
RESET
RESET
CD-CH
SW
P.CON PROTECTION
INHIBIT SW
BACK-UP
5V DRIVER
SW DETECTION
BACK-UP
SW
DSM1SD2 or
D380 MA4047-M:B LINE
GND LINE
SIGNAL LINE
1.3V
0.8V
3.5V
0V
8.0V
3.5V
0.8V
1.3V
0V 4.4V
0V 5V
0V 5V
0V
5V
0V
4.0V
4.0V
4.0V
4.0V
4.0V
4.0V
5.0V
0V 3.5V
0V
8.0V
4.0V
0V 5V
5.0V
0V 5V
0V
5.0V
0V or 5.0V
0V 5V
0V 5V
0V
0V 5V
5V
0V
0V 5V
5V
0.9V
0V or 5.0V
5V
0V
0V or 5.0V
0V
5.0V
0V
5.0V
5.0V
0V 4V
0V 4V
1.6V
14.4V
4.8V
0V
7.3V
0V
7.2V
7.2V
3.3V
14.4V
0V
7.3V
7.3V
7.3V
7.3V
7.2V
0V
7.2V
7.3V
7.3V
7.3V
7.3V
0V
7.3V
0V
0V 2.5V
5.0V 0V 4V
0V
5.0V
5.0V
+B+B
126
345
ME1 (D40-1136-05)
HD1
S3
M
M1
S1 S2
FWD/REV
GND
HEAD R
HEAD COM
HEAD L
T.MUTE
GND
MOT GND
MOT+B
GND
PACK IN
Lch
12
FWD
REV
Rch
Ref.99
6
345
CAUTION : For continued
safety, replace safety critical
components only with manu-
facturer's recommended parts
(refer to parts list).
Indicates safety critical
components. To reduce the
risk of electric shock, leakage-
current or resistance measure-
ments shall be carried out
(exposed parts are acceptably
insulated from the supply cir-
cuit) before the appliance is
returned to the customer.
• DC voltages are as mea-
sured with a high imped-
ance voltmeter. Values may
vary slightly due to varia-
tions between individual
instruments or/and units.
!

KLMNOPQRST
1
2
3
4
5
6
7
+5V +5V
+B
+B
+B
+B +B
12
11
10
9
8
7
6
5
4
3
2
1
PANEL SW
L-DATA S
L-CLK
L-CE
L-DATA L
L-RES
u-GND
PAN 5V
RST
ILL-GND
ILL+B
ESD-GND
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
1
2 3
4
5 6 7 8
9
10
11
12 13
14
15 16 17 18
19
20
21
22 23
24
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
KS6 KS5
KS4
KS3 KS2
KS1
COM3 COM2
COM1
S55
S54
S53 S52
S51
S50
S49
S48 S47 S46 S45
S44
S43 S42
S41
S40
S39
S38
S37
S36
S35
S34
S33
S32
S31
S30
S29
S28
S27
S26
S25
KEY S4 S5 S6 S7 S8 S9 S10 S11 S12 S13 S14 S15 S16 S17 S18 S19 S20 S21 S22 S23 S24
KI1
KI2
KI3
KI4
KI5
VDD
VDD1
VDD2
VSS
TEST
OSC
RES
DATA L
CE
CL
DATA S
KI1
KI2
KI4
KI3
C3 0.047
C1 1000P
C2 0.047
R7 56K
C4 0.01
R21 4.7
R8 1K
R9 47K
79
80
78
76
77
78
77
79
76
R6 100
R3 100
R5 100
R4 100
R2 1K
80
KS5
25
4
5
6
7 8
9
10
11
12 13
14
15 16 17 18
19
20
21
22 23
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
KS4
KS3 KS2
KS1
C3 C2
C1
55
54
53 52
51
50
49
48 47 46 45
44
43 42
41
PL2 PL1
13 13
R18
470
R15
470
R14
330
R13 R12
330
R10
470
R11
330
KS1
KS2
KS3
KS4
KS5
KI4
KI3 KI2
KI1
50
49
48 47 46 45
44
43 42
41
40
39
38 37 36 35
34
33 32
31
30
29
28 27 26 25
24
23 22
21
20
19
18 17 16 15
14
13 12
11
10
9
8 7 6 5
4
3 2
1
S19 S18 S17 S16 S15 S14 S13 S7 S8 S6 S9 S5 S11 S10 S12 S4 COM3 COM2 COM1 S55 S53 S54 S51 S52 S49 S50 S48 S46 S47 S45 S44 S43 S42 S41 S40 S39 S38 S37 S36 S35 S34 S33 S32 S31 S30 S29 S28 S27 S26 S25
54
53 52
51
S23 S22 S21 S20
25 26 27 28
29
30
31
32 33
34
35 36 37 38
39
40
41
42 43
44
45 47 46 48 50
49
52
51
54
53 55
C1
C2 C3
4
12 10
11
5
9
6
8 7
13
14
15 16 17 18
19
20
21
22 23
R17
3
3
0V 5V
5.0V
3.3V
1.7V
0V
5.0V
5V
3.3V
0V
5V
0V
5V
1.7V
3.3V
5V
0V
0V
5V
0V
5V
5V
0V
B LINE
GND LINE
J1 Q1
2
1
CLK ATT
AM6
5
VOL+
FMAUDIO
D14 : ∗
D1-13,15 : ∗
Q1 : DTA114EK
IC1 : LC75883E
J3
X14-
1/2
LCD DRIVER
DETECTION
PANEL
AUTO VOL-
T.UP
43
T.DOWN
SRC
∗
ED1
RST
∗D14
∗D12
∗D9
∗D6
∗D4
∗D1
∗D15
∗D13
∗D10
∗D7
∗D5
∗D2
∗D11
∗D8
∗D3
D17
: MA3062-MD17
IC1
SWITCH UNIT (X16-1512-7X)
KRC-2902YA/G (2/2)
A
LCD
10K
10K
2-71
MODEL NAME
KRC-2902YA
UNIT No.
2-70
KRC-2902YG
(X16-1512-7X)
B30-1566-05
D1-13,15
B30-1565-05 B30-1511-05
D14
B30-2025-05 B38-1099-05
ED1
B38-1037-05
CAUTION : For continued safety, replace safety critical components
only with manufacturer's recommended parts (refer to parts list).
Indicates safety critical components. To reduce the risk of electric
shock, leakage-current or resistance measurements shall be carried
out (exposed parts are acceptably insulated from the supply circuit)
before the appliance is returned to the customer.
• DC voltages are as measured with a high impedance voltmeter.
Values may vary slightly due to variations between individual
instruments or/and units.
!
2SB1565
DTA114EK
DTA124EK
DTA144EK
DTC114YK
DTC124EK
DTC144EK
KRC103S
2SA1036K
2SC2412K
2SB1548
2SB1277
2SB1443
2SA1037K
KRA102S
KRC104S
LA3161

KRC-2902YA/G
EXPLODED VIEW (MECHANISM)
Parts with the exploded numbers larger than 700 are not supplied.
AB
1
2
3
31
54
4
99
101
115
53
111
102
102
12
103 111
31
33
14
102
114
52
39
10
40
34
58
57
39
9
35
112
113
7
626
25
HD1
56
100
106x2
37
36
38
M1 20
5
1
23
22
105x2 113
112
16
18
17
19 102
104
13