Kenwood KRC-16A, KRC-191A, KRC-265LA Service Manual

CASSETTE RECEIVER

KRC-16A/G/YA/YG

SERVICE MANUAL

© 2001-10 PRINTED IN KOREA
B51-7857-00 (K) 2161

KRC-191A/G/YA/YG
KRC-265LA/LG/RG
KRC-26A/G/YA/YG
KRC-291A/G/YA/YG

KRC-265RG

KRC-16A/G/YA/YG (E)

KRC-191A/G/YA/YG (E)

KRC-265RG (M)

45W x 4

KRC-265L

45W x 4

AUTO

AME

KRC-291

45W x 4

KRC-26

45W x 4

KRC-191

45W x 4

T.CALL

KRC-16

45W x 4

T.CALL

KRC-26A/G/YA/YG (E)

KRC-291A/G/YA/YG (E)

KRC-265LA/LG (M)

DC1

242

201

262

261

216

x2

263

The following reference numbers with accessory parts are the same reference numbers
used on EXPLODED VIEW and PARTS LIST.

2

IC1

KEY

PAN 5V

MUTE

B.U. DET.

B.U.

ACC

P-CONT.

MUTE

PRE

POWER IC

EQ. AMP.

CH ISO AMP

NC,MPX

E-VOL.

CD/MD
CHANGER

FRONT Lch

FRONT Rch

REAR Lch

REAR Rch

J2

LCD DRIVER

LCD

ME1

MAIN

TAPE MECHA.

IC5

Lch

Rch

PRE OUT

IC2

IC4

IC3

SP OUT

REAR

J4

PAN IN SW

ACC DET.

P-CONT.

J2

J5

IC1

F/E

J1

FM+B

Q201

AM+B

Q203

AM BPF

FM BPF

C154,R206

C153,R207

Q320

Q450,451

Q49

Q50

Q350,351,370

Q53

SW 5V

Q54-57

8V

Q58-61

ILLUMI.

B.U. 5V

Q51,52

SYSTEM u-COM

S1

S2

S3

RST SW

Q301

D1-15

PL1,2

ANT.

TEL MUTE

DECODER

RDS

IC7

Q501,502

MP SW

40W

RST IC

RST

IC6

ED1

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

P.ON

ACC DET

B.U. DET

SCL

MUTE

SDA

P CON

PANEL

RESET

L CLK

L DATA S

L DATA L

FWD/REV

MOTOR

CH CON

DATA H

DATA C

REQ H

REQ C

CH CLK

Rch

COM

Lch

MP IN

AM

MPX

OUT RR

OUT LR

OUT RF

Rch

LEVEL

SCL

SDA

OUT LF

Rch

STBY

MUTE

Rch

Lch

T-MUTE

FWD

REV

B.U.5V

8V

B.U.

CH RST

S MUTE

8

5

10

B.U.5V

AM+B

VDD 5V

PACK IN

L RES

PHONE

CH

MUTE

BEEP

SVR

AMP. STBY

SVR

AC GND (BEEP)

Lch Lch

Rch

Lch

1200mV

TAPE :1681mV
CD/MD-CH :3529mV

AM :772mV

FM :1339mV

8V

RF GND

OSC GND

IF2 +B

AUDIO OUT

8V

S-METER

SD

PLL-SCL

PLL-SDA

M1

PLAY
HEAD

L/R

55.6mV

B.U.5V

SW 5V

8V

B.U.5V

AM: 170mV

FM: 213mV

TAPE

PACK IN

(FF/REW)

AMP. MUTE

FF/REW

B.U.5V

R QUAL

IF COUNT

R CLK

R DATA

SW 5V

MP OUT

QUAL

AFC

NOISE

B.U.5V

ILL

L CE

(X16)

M

KRC-16,191,265L/R,26,291 (E,E,M,E,E)

A1

TEL DET

D380

5V

R205

KRC-16,191,265L/R,26,291

BLOCK DIAGRAM

KRC-16,191,265L/R,26,291

COMPONENT DESCRIPTION

SYNTHESIZER UNIT (X14-687x-xx)

REF No. FUNCTION OPERATION

IC1 SYSTEM µ-COM Controls the unit.

IC2 E-VOLUME Controls the volume and selects source.

IC3 MUTE 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.

IC7 RDS DECODER Decodes the radio data.

Q49 ACC 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

Q151 SVR FORCED DISCHARGE SW Works when the amplifier mute works.

Q153 PRE OUT MUTE SW

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

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.

Q450,451 PRE OUT MUTE SW

Q500 AUDIO OUTPUT BUFFER For RDS decoder.

Q501,502 AFC TIME CONSTANT SW Works during receiving FM signal.

Q503 NOISE BUFFER For noise level detection.

Works when the back-up current is detected

or the changer mute works or system µ-com mute works.

Works when the back-up current is detected

or the changer mute works or system µ-com mute works.

Works when the back-up current exists and the panel

is attached on the unit.

Works when the back-up current is detected

or the changer mute works or system µ-com mute works.

3

KRC-16,191,265L/R,26,291

MICROCOMPUTER'S TERMINAL DESCRIPTION

(X14-) IC1 : µ-COM

PORT No. PORT NAME I/O FUNCTION OPERATING CONDITION

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 IC2 SEL 1 I Selector. "L" : Normally.

9 IC2 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.

33 VSS 1 - GND. -

34 - - - -

35 PLL CLK O Front-end communication clock. -

36 PLL DATA I/O Front-end communication data. -

37 AM +B 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. -

"H" : Signal exists.

"L" : Signal does not exist.

4

KRC-16,191,265L/R,26,291

MICROCOMPUTER'S TERMINAL DESCRIPTION

(X14-) IC1 : µ-COM

PORT No. PORT NAME I/O FUNCTION OPERATING CONDITION

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. -

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.

77 PHONE I -

78 NOISE I FM noise detection. -

79 AV CONT O A/D converter reference voltage. -

80 - - - -

"H" : S-meter exists.

"L" : S-meter does not exist.

Navigation mute : 2.5V or more.

Telephone mute : 1V or less.

5

KRC-16,191,265L/R,26,291

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

6

KRC-16,191,265L/R,26,291

Einstellung des Kopfwinkels

Vorgehensweise bei der Kopfhöhen-Einstellung

• Während des Bandlaufs in Vorwärtsrichtung die Schrauben F und F' so

einstellen, daß die Linie A eines 2-Linien-Bands (2-LINE TAPE) durch
die Mitte der Kopfabschirmplatte (Zentrum des Mittelbereichs) verläuft.

• Während des Bandlaufs in Rückwärtsrichtung die Schrauben R und R '

so einstellen, daß die Linie B eines 2-Linien-Bands (2-LINE TAPE)
durch die Mitte der Kopfabschirmplatte (Zentrum des Mittelbereichs)
verläuft.

• Nachdem die obige Einstellung abgschlossen ist, die Bandlaufrichtung
umkehren und die Ausrichtung in Vorwärtsrichtung noch einmal
überprü fen. Wenn eine Abweichung festgestellt wird, ist diese
Einstellung zu wiederholen. (Verwendetes Band: SCC-1659, hergestellt
von A-BEX)

Head Angle Adjustment

Head height alignment procedure

• During FWD transport adjust screws F and 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 R and 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)

(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

ADJUSTMENT

7

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

X16-151x-xx (J74-1300-02)

SWITCH UNIT SWITCH UNIT

X16-151x-xx (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

BE

Q1

IC1

D17

J1

A BDCE

Ref.No Address

IC1 3D

Q1 4D

SWITCH UNIT
(X16-151x-xx)

PC BOARD

1

Component side view Foil side view

2

3

4

5

6

7

8

Refer to the schematic diagram for the value of resistors and capacitors.