Kenwood KRC-189 Service Manual

CASSETTE RECEIVER

KRC-189

SERVICE MANUAL

Escutcheon (B07-2188-02)

Lever (D10-3031-04)×2

Knob (EJECT) (K27-3554-03)

Cassette lid (A53-1677-03)

Stay (J54-0606-04)

Knob (REW) (K27-3556-04)

LCD (B51-1024-05)

Knob (FF) (K27-3555-04)

KRC-189

Panel assy (A64-2313-02)

Screw set (N99-1632-05)

Mounting hardware assy (J21-9491-13)

DC cord (E30-4784-05)

IC1

KEY

MUTE

B.U DET.

B.U

ACC

P-CONT.

MUTE

PRE

POWER IC

EQ. AMP

AMP

NC/MPX

E-VOL.

FRONT Lch

FRONT Rch

REAR Lch

REAR Rch

LED

TAPE MECHA

MAIN

IC5

1 Lch

2 Rch

PRE OUT

IC2 IC4

IC3

SP OUT

REAR

RST SW

RST IC PST9130NR

IC6

ACC DET.

P-CONT.

ANT-CONT

HD74HC27FP

40W TDA7384A

FM+B

Q201

AM+B

Q203

AM BPF

FM BPF

Q450,451

Q62

Q50

Q350

Q53

SW5V

Q56

Q60

ILLUMI

BU5V

Q51

SYSTEM u-COM

TDA7400D

RST

Q370

ANT-CONT

LA3161

M38258MCD FP

7SEG LCD

ED1

FM ANT AM ANT RF GND

FM+B

AM+B OSC GND OSC GND OSC GND

PLL +B

IFC OUT

SDA SCL

DIG GND

IF1+B

IF1 GND

S-METER

IF2 GND

FM+B

PON

ACC DET

B.U DET

SCL

MUTE

SDA

P CON

RESET

FWD/REV

MOTOR

Rch

COM

Lch

TAPE

MP IN

MPX

OUT RR

OUT LR

OUT RF

LEVEL

SCL

SDA

OUT LF

STBY

MUTE

Rch

Lch

T-MUTE

FWD

REV

B.U

SMUTE

(FF/REW)

BU5V

AM+B

VDD 5V

PACK IN

ANT CON

BEEP

SVR

AMP. STBY

SVR

AC GND(BEEP)

Rch

Lch

TAPE :1681mV

AM :546mV

FM :1781mV

RF GND

OSC GND

IF2 +B

AUDIO OUT

S-METER

PLL-SCL

PLL-SDA

HEAD

55.6mV

BU5V

B.U.5V

BU5V

AM: 170mV

FM: 400mV

PAC K

PLAY

FF/REW

ILL

KS0-KS4

KI0-KI3

SEG1-SEG22

COM1-COM3

AMP. MUTE

BU5V

(X13)

F/E

KRC-189

BLOCK DIAGRAM

MICROCOMPUTER’S TERMINAL DESCRIPTION

Microcomputer (M38258MCD070FP : IC1 : X14)

●Terminal description

Pin No.

19-25 O (NC) Not used.

36,37 O (NC) Not used.

I/O Pin Name Description

1 I (NC) Not used.

2 I VL1 LCD power input.

3-5 I KI0-2 Key return input.

6-9 O KS0-3 Key scan output.

10 I SMETER Signal meter.

11 O KS4 Key scan output.

12 O BEEP Beep output.

13 O (NC) Not used.

14 O MOTOR Mechanism motor ON/OFF.

15 I FF/REW

16 I PACK_IN

17 I KI3 Key return input.

18 I FWD/REV

26 I SD Station detection.

27 O PLL_CLK IC3 clock output.

28 I/O PLL_DATA IC3 data input/output.

29 I IFC AM bandwidth.

30 O AM+B AM power output.

31 O FM+B FM power output.

32 O SCK IC2 clock output.

33 I/O SDA IC2 data input/output.

34 O (NC) Not used.

35 I RESET Reset input.

38 - X_IN Clock input.

39 - X_OUT Clock output.

40 - Vss Power input (0 V).

41 I IC2_TYPE1 IC2 constant switching.

42 I IC2_TYPE2 IC3 constant switching.

43 O (NC) Not used.

44 I SEL1 Destination type switching.

45 I SEL2 Destination type switching.

46 O MUTE Muting ON/OFF.

47 O STBY Power IC standby control.

48 O SVR Power IC SVR control.

49 I ACC_DET Acc detection.

50 I BU_DET

Mechanism FF/RWD detection.

Mechanism cassette pack-in detection.

Mechanism play direction detection.

Momentary power down detection.

KRC-189

Pin No.

58-64 O (NC) Not used.

65,66 O (NC) Not used.

67,68 O (NC) Not used.

69-90 O SEG22-1 LCD segment output.

I/O Pin Name Description

51 O P_MUTE Power IC muting control.

52 O ANT_CON External antenna control.

53 O P_CON Power control output.

54 O ILLUM_ON Illumination control.

55 O (NC) Not used.

56 O SW5 5V power control.

57 O EQ_MUTE Equalizer muting.

91 - Vcc Power input (5 V).

92 - VREF A/D reference voltage input.

93 - Avss Analog power input (Vss).

94 O (NC) Not used.

95 O COM3 LCD common output.

96 O COM2 LCD common output.

97 O COM1 LCD common output.

98 I VL3 LCD power input.

99 I VL2 LCD power input.

100 I (NC) Not used.

KRC-189

ADJUSTMENT

Set the controls and switches as follows. BALANCE : center position BASS : center position LOUD : OFF DOLBY NR : OFF FADER : center position TREBLE : center position

No. ITEM

CASSETTE DECK SECTION

[1]

[2]

HEAD

HEIGHT

HEAD

AZIMUTH

TAPE

SCC-1659 – TAPE PLAY

TCC-153

10kHz

OUTPUT

SETTINGS

Connect a

AC voltmeter

to SP out.

RECEIVER

SETTINGS

TAPE PLAY

ALIGNMENT

POINTS

Head Height

Screw

Head Azimuth

Screw

(2-LINE TAPE)

(FWD)

ALIGN FOR

1) During FWD transport adjust (F) and (F’) so that line A of 2-LINE TAPE passes trough the center of the head shield plate (core center area)

2) During RVS transport adjust screws (R) and (R’) so that line B of 2-LINE TAPE passes trough the center of the head shield plate (core center area)

3) 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)

Adjust the azimuth for each Lch/Rch or FWD/RVS becomes maximum

TAPE SPEED

(RVS)

HEIGHT (FWD)

HEIGHT/AZIMUTH

(FWD)

’’

HEIGHT (RVS)

HEIGHT/AZIMUTH

(RVS)

+ 9 hidden pages