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
KRC-29Y/35R,379R/RY,479R/RY,481R
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 DATA
PLL CLK
PLL CE
HI UP ADJ
FM+B
AM+B
A8V
SW5V
(X13)
(X14)
MM
KRC-479R/RY
KRC-29Y35R,379R/RY,481R
SW5V
B.U.
LO/DX
SD
S METER
PLL-DATA
PLL-CE
SUB+
SUB-
SW5V
ACC DET
B.U DET
SCL
MUTE
SDA
EN1
EN2
EN3
PANEL
RESET
L RES
L CLK
L DATA S
L DATA L
DSI
FWD/REV
T MODE
MOTOR
CH MUTE
NOISE
DATA H
DATA C
REQ H
REQ C
CH RST
CH CONT
CH CLK
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
PACK
T-END
STBY
MODE
FWD
REV
B.U.5V
A8V
B.U.
SMUTE
B.U.14V
B.U.
A8V
8
5
10
IN
PLAY HEAD
B.U.5V
AFS
R QUAL
R CLK
R DATA
PACK IN
M-STBY
T END
L CE
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
TAPE :1786mV
CD/MD-CH :3546mV
AM :850mV
FM :1345mV
TAPE :1912mV
CD/MD-CH :3795mV
AM :910mV
FM :1440mV
PLL-CLK
SW 5V
MUSIC
MSCONT
EQ MUTE
MUSIC
MSCONT
MUTE
A8V
IC6
RDS
DECODER
SW 5V
SYSTEM u-COM
IC1
KEY
PAN 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
REGULATOR
IC7
LCD DRIVER
LCD
TAPE MECHA
MAINSUB
IC9
PRE OUT
IC2
IC4
IC8
IC12
SP OUT
SUB MOT
AVR
MOTOR
J4
DSI
REMO
RST SWPAN IN SW
GREEN
RED or
RST IC
IC11
ACC DET
TEL DET TEL MUTE
J2
VOLTAGE
CONNECTOR
DC
J6
DRIVER
IC1
BLOCK DIAGRAM
2
COMPONENT DESCRIPTION
SYNTHESIZER UNIT (X14-641x-xx)
KRC-29Y/35R,379R/RY,479R/RY,481R
REF.
No.
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
Q201 NOISE DETECTION Detects noise.
Q221-224 PREOUT MUTE Mutes when the base terminal voltage level becomes "H".
Q251 POWER IC SVR SW
Q301 LOCAL SEEK SW Changes to the local seeking after the base terminal voltage becomes "H".
Q501 MOTOR DRIVER AVR
Q551 MAIN MOTOR SW Works when the base terminal voltage becomes "L".
Q552 MAIN MOTOR SW Works when the base terminal voltage becomes "H".
FUNCTION OPERATION
Works when the base terminal voltage level becomes "L". Supplies
VDD to panel.
Discharges the capacitor's voltage of SVR terminal after the base
termial voltage becomes "H".
Works when the base terminal voltage becomes "H". Supplies the
power to the motor driver.
SWITCH UNIT (X13-989x-xx)
REF.
No.
IC1 LCD DRIVER
IC2 REMOTE SENSOR
Q1 KEY SCAN SW Receives key signal when the base terminal voltage becomes "L".
Q2 KEY ILLUMINATION SW
Q3 KEY ILLUMINATION SW
FUNCTION OPERATION
Key illumination color becomes green when the base terminal voltage
becomes "H".
Key illumination color becomes red when the base terminal voltage
becomes "H".
3
KRC-29Y/35R,379R/RY,479R/RY,481R
MICROCOMPUTER'S TERMINAL DESCRIPTION
(X14-) IC1 : µ -COM
PORT
PORT NAME I/O FUNCTION OPERATING CONDITION
No.
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.
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.
"H" : Station exists.
"L" : Station does not exist.
4
KRC-29Y/35R,379R/RY,479R/RY,481R
MICROCOMPUTER'S TERMINAL DESCRIPTION
(X14-) IC1 : µ -COM
PORT
45-47 - - -
PORT NAME I/O FUNCTION OPERATING CONDITION
No.
41 P.CON-DET I P.CON short-circuited detection.
42 CH-CONT O Changer control.
43 - - -
44 CH-REC H O Changer request.
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.
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.
77 T-MODE I Cassette tape mode detection.
78 PHONE I
79 NOISE I Noise detection during FM mode.
80 AV CONT O Reference voltage.
Navi mute : Over 2.5V.
Tel mute : less than 2.5V.
"H" : Signal does not exist.
"L" : Signal exist.
"H" : SD exists.
"L" : SD does not exist.
5
KRC-29Y/35R,379R/RY,479R/RY,481R
TEST MODE
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 should not released in conditions of ACC OFF, power OFF, momentary power down or
the panel off.
3. Test mode
• Blanking Skip (B.S) OFF.
• Eject a tape by pressing "ATT" key.
4. Audio adjustment
• Enter the audio mode by pressing the "AUD" key or "OPEN/CLOSE" key on the remote controller.
• Set the volume level to be -10dB. In that case, "30" should be shown on the display.
• Loudness OFF.
• The BASS/MIDDLE/TREBLE and BALANCE/FADER can be adjusted to the full-boost/full-cut and full-front/full-
rear each by pressing the "UP" and "DOWN" keys.
5. Menu mode
• Enter the menu mode by pressing "CLK" key or "DNPP" key on the remote controller.
• Only on models with RDS function, Local Seeking should be first menu.
6
KRC-29Y/35R,379R/RY,479R/RY,481R
BALANCE/FADER/BASS/TREBLE : CENTER
T.ADV/METAL/DOLBY NR/AUTO : OFF
No. ITEM
INPUT
SETTINGS
OUTPUT
SETTINGS
RECEIVER
SETTINGS
ALIGNMENT
POINTS
ALIGN FOR FIG.
CASSETTE DECK SECTION
1 AZIMUTH
TCC-153
10KHz
SP OUT TAPE PLAY
Head azimuth
screw
(FWD/REV)
(ME1)
Adjust so that output
level in playing "FWD"
and "REV" becomes
maximum each.
(b)
(b) AZIMUTH
PANEL FRONT
FWD
REV
ADJUSTMENT
7