Kenwood KRC-29-Y, KRC-35-R, KRC-379-R, KRC-379-RY, KRC-479-RY Service manual

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 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

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

KRC-29Y/35R,379R/RY,479R/RY,481R

6

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.

7

ADJUSTMENT

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