CASSETTE RECEIVER
KRC-29Y/35R
SERVICE MANUAL
© 2001-1 PRINTED IN KOREA
B51-7734-00 (K) 2150
KRC-379R/RY
KRC-479R/RY
KRC-29Y (E)
KRC-29
CD MD-Changer Control
40W x 4
MECHANISM EXTENSION CORD
W05-0477-00 (7P)
W05-0609-00 (10P)
KRC-481R
SCRL
KRC-35R (E)
KRC-35R
CD MD-Changer Control
40W x 4
SCRL
T. CALL
KRC-379R/RY (E)
KRC-379R
CD MD-Changer Control
40W x 4
SCRL
T. CALL
TI
VOL ADJ
KRC-479R/RY (E)
KRC-479R
CD MD-Changer Control
45W x 4
SCRL
T. CALL
KRC-481R (M)
KRC-481R
CD MD-Changer Control
45W x 4
SCRL
T. CALL
TI
VOL ADJ
262
261
242
223x2
263
DC1
201
The following reference numbers with accessory parts are the same reference numbers
used on EXPLODED VIEW and PARTS LIST.
246
TI
VOL ADJ
TI
VOL ADJ
T. CALL
40%
KRC-29Y/35R,379R/RY,479R/RY,481R
2
BLOCK DIAGRAM
F/E
FM
ANT
AM
ANT
RF
GND
FM+B
AM+B
AM
LO/DX
FM
LO/DX
IF
SELECT
RDS
OUT
FM
SD
OUT
REQUEST
K2I-VTH
VCO-GND
FSD
OUT
FM
DET
OUT
AM
DET
OUT
IF
GND
COMMON+B
P-ON
5V
DIG
GND
PLL
DA
T
A
PLL
CLK
PLL
CE
HI
UP
ADJ
FM+B
AM+B
A8V
SW5V
(X13)
(X14)
M
M
KRC-479R/R
Y
KRC-29Y35R,379R/R
Y
,481R
SW5V
B.U.
LO/DX
SD
S
METER
PLL-DA
T
A
PLL-CE
SUB+
SUB-
SW5V
ACC
DET
B.U
DET
SCL
MUTE
SDA
EN1
EN2
EN3
PANEL
RESET
LRES
LCLK
LD
ATAS
LD
ATAL
DSI
FWD/REV
TMODE
MOTOR
CHMUTE
NOISE
DATA
H
DATA
C
REQH
REQC
CHRST
CHCONT
CHCLK
Rch
COM
Lch
Lch
Rch
MP
IN
AFS
QUAL
AM
MPX
OUT
RR
OUT
RL
OUT
FR
CD-GND
LEVEL
SCL
SW5V
SDA
SCL
SDA
OUT
FL
S-GND
Rch
Rch
STBY
MUTE
EN2
EN3
ILLUMI
EN1
AUDIO
VCC
B.U.5V
AM+B
FM+B
P-CON
FM+B
AM+B
A8V
B.U.5V
Rch
Lch
P
ACK
T
-END
STBY
MODE
FWD
REV
B.U.5V
A8V
B.U.
SMUTE
B.U.14V
B.U.
A8V
8
5
10
IN
PLA
Y
HEAD
B.U.5V
AFS
R
QUAL
R
CLK
R
DA
T
A
PACK
IN
M-STBY
TEND
LC
E
B.U.5V
REMO
SW5V
GREEN
RED
B.U.5V
PHONE
BEEP
SVR
P-MUTE
P-STBY
SVR
AC
GND(BEEP)
Lch
Lch
Rch
Lch
1200mV
AM
:
160mV
FM
:
213mV
T
APE
:1786mV
CD/MD-CH
:3546mV
AM
:850mV
FM
:1345mV
T
APE
:1912mV
CD/MD-CH
:3795mV
AM
:910mV
FM
:1440mV
PLL-CLK
SW
5V
MUSIC
MSCONT
EQMUTE
MUSIC
MSCONT
MUTE
A8V
IC6
RDS
DECODER
SW
5V
SYSTEM
u-COM
IC1
KEY
P
AN
5V
MUTE
THERMO
PROTECTION
EEPROM
B.U.
DET
SURGE
DET
B.U.
ACC
P-CONT
MUTE
PRE
POWER
IC
DRIVER
IC10
EQ
AMP
E-VOL
CD/MD
CHANGER
FRONT
Lch
FRONT
Rch
REAR
Lch
REAR
Rch
FRONT
Lch
FRONT
Rch
REAR
Lch
REAR
Rch
J2
REGULA
T
O
R
IC7
LCD
DRIVER
LCD
T
APE
MECHA
MAIN
SUB
IC9
PRE
OUT
IC2
IC4
IC8
IC12
SP
OUT
SUB
MOT
AV
R
MOT
OR
J4
DSI
REMO
RST
SW
P
AN
IN
SW
GREEN
RED
or
RST
IC
IC1
1
ACC
DET
TEL
DET
TEL
MUTE
J2
VOL
T
AGE
CONNECT
OR
DC
J6
DRIVER
IC1
REF.
No.
FUNCTION
OPERATION
IC1
LCD DRIVER
IC2
REMOTE SENSOR
Q1
KEY SCAN SW
Receives key signal when the base terminal voltage becomes "L".
Q2
KEY ILLUMINATION SW
Key illumination color becomes green when the base terminal voltage
becomes "H".
Q3
KEY ILLUMINATION SW
Key illumination color becomes red when the base terminal voltage
becomes "H".
REF.
No.
FUNCTION
OPERATION
Q1
P.CON. DETECTION
Detects P.CON voltage
Q10
BACK-UP DETECTION
Detects the back-up voltage.
Q11
SERGE DETECTION
Detects serge voltage.
Q20
ACC DETECTION
Detects ACC voltage.
Q40
PREOUT MUTE DRIVER Mutes when the base terminal voltage level becomes "L".
Q50
5V SW
Works when the base terminal voltage level becomes "L".
Q101
DSI SW
LED for DSI works when the base terminal voltage level becomes "H".
Q151
PANEL 5V SW
Works when the base terminal voltage level becomes "L". Supplies
VDD to panel.
Q201
NOISE DETECTION
Detects noise.
Q221-224 PREOUT MUTE
Mutes when the base terminal voltage level becomes "H".
Q251
POWER IC SVR SW
Discharges the capacitor's voltage of SVR terminal after the base
termial voltage becomes "H".
Q301
LOCAL SEEK SW
Changes to the local seeking after the base terminal voltage becomes "H".
Q501
MOTOR DRIVER AVR
Works when the base terminal voltage becomes "H". Supplies the
power to the motor driver.
Q551
MAIN MOTOR SW
Works when the base terminal voltage becomes "L".
Q552
MAIN MOTOR SW
Works when the base terminal voltage becomes "H".
KRC-29Y/35R,379R/RY,479R/RY,481R
3
COMPONENT DESCRIPTION
SYNTHESIZER UNIT (X14-641x-xx)
SWITCH UNIT (X13-989x-xx)
KRC-29Y/35R,379R/RY,479R/RY,481R
4
MICROCOMPUTER'S TERMINAL DESCRIPTION
PORT
No.
PORT NAME I/O
FUNCTION
OPERATING CONDITION
1
DSI
O
DSI control.
2
PANEL
I
Panel detection.
"L" : Panel exists.
3-
-
-
4
AVSS
-
GND.
5
L-RST
O
LCD driver reset.
6
L-CE
O
LCD driver chip enable.
7
AVREF 1
I
Reference voltage
8-
-
-
9
PLL-DATA
I/O
Front-end communication data.
10
PLL-CLK
O
Front-end communication clock.
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
R-DATA
I
RDS data.
15
R-QUAL
I
RDS QUAL.
16
CH-DATA C
I
Changer communication data.
17
CH-DATA H
O
Changer communication data.
18
CH-CLK
I/O
Changer communication clock.
19
M-STBY
I
Cassette tape stand-by detection.
"H" : Stand-by.
20
T-END
I
Tape end detection.
"H" : Run.
"L" : Stop.
21
ACC-DET
I
ACC detection.
22
BU-DET
I
Back-up detection.
23
IC2 TYPE 0
I
For service.
"L" : Normally.
24
IC2 TYPE 1
I
For service.
"L" : Normally.
25
TYPE 0
I
Destination discrimination.
26
TYPE 1
I
Destination discrimination.
27
TYPE REF
O
Reference voltage for destination and service.
28
MOTOR
O
Cassette mechanism motor.
"H" : ON.
"L" : OFF.
29
PLL-CE
O
Front-end communication chip enable.
30
SD
I
Station detection.
"H" : Station exists.
"L" : Station does not exist.
31
ASF
O
Noise detection time constant switch.
32
LO/DX
O
Local seeking switch.
"H" : LO.
"L" : DX.
33
VSS 1
-
GND.
34
P-MUTE
O
Power amplifier muting.
35
SVR
O
SVR control.
36
-
-
-
37
IC2-SCL
O
E-volume communication clock.
38
IC2-SDA
I/O
E-volume communication data.
39
MUTE
O
Muting control.
40
P-STBY
O
Power amplifier stand-by.
(X14-) IC1 : µ -COM
KRC-29Y/35R,379R/RY,479R/RY,481R
5
MICROCOMPUTER'S TERMINAL DESCRIPTION
PORT
No.
PORT NAME I/O
FUNCTION
OPERATING CONDITION
41
P.CON-DET
I
P.CON short-circuited detection.
42
CH-CONT
O
Changer control.
43
-
-
-
44
CH-REC H
O
Changer request.
45-47
-
-
-
48
EN2-1
O
Power supply IC control.
49
EN2-0
O
Power supply IC control.
50
BEEP
O
Buzzer.
51
EN3
O
Power supply IC control.
52
EN1
O
Power supply IC control.
53
SW 5V
O
P.ON 5V control.
"H" : OFF.
"L" : ON.
54
MUSIC
I
Tape signal detection.
"H" : Signal does not exist.
"L" : Signal exist.
55
MS-CONT
O
Tape advanced sensitivity control.
"H" : Play.
"L" : FF/REW.
56
EQ-MUTE
O
Cassette tape muting.
"H" : ON.
"L" : OFF.
57
FWD/REV
I
Cassette tape running direction detection.
"H" : FWD.
"L" : REV.
58
SUB+
O
Sub motor control.
59
SUB-
O
Sub motor control.
60
RESET
I
System reset.
61
REMOTE
I
Remote control.
62
R-CLK
I
RDS clock.
63
CH-REQ C
I
Changer request.
64
PACK-IN
I
Cassette tape pack-in detection.
65
KEY-REQ
I
Key signal detection.
66
-
-
-
67
VSS 0
-
GND.
68
VDD 1
-
VDD.
69
X2
-
Main system clock.
70
X1
I
Main system clock.
71
IC
-
-
72
-
-
-
73
XT1
-
VDD.
74
VDD 0
-
VDD.
75
AVREF 0
I
Reference voltage.
76
S-METER
I
SD detection.
"H" : SD exists.
"L" : SD does not exist.
77
T-MODE
I
Cassette tape mode detection.
78
PHONE
I
Navi mute : Over 2.5V.
Tel mute : less than 2.5V.
79
NOISE
I
Noise detection during FM mode.
80
AV CONT
O
Reference voltage.
(X14-) IC1 : µ -COM