Kenwood KRC-15-RG, KRC-179-RG, KRC-179-RA, KRC-179-RYA, KRC-179-RYG Service manual
...
CASSETTE RECEIVER
KRC-15RG
SERVICE MANUAL
© 2000-10 PRINTED IN KOREA
B51-7684-00 (K) 2161
KRC-179RA/RG/RYA/RYG
KRC-25RA/RG
ANTENNA ADAPTOR
(T90-0523-05)
(Except KRC-281RG)
KRC-279RA/RG/RYA/RYG
KRC-281RG
KRC-279R
CD/MD-CHANGER CONTROL
KRC-25R
CD/MD-CHANGER CONTROL
KRC-15R
KRC-179R
KRC-281R
CD/MD-CHANGER CONTROL
KRC-15RG (E)
KRC-179RA/RG/RYA/RYG (E)
KRC-25RA/RG (E)
PLASTIC CABINET ASSY
(A02-1486-13)
LEVER
(D10-3031-04) x2
MOUNTING HARDWARE ASSY
(J21-9491-13)
DC CORD
(E30-xxxx-xx)
(Refer to the parts list.)
STAY
(J54-0606-04)
SCREW SET
(N99-1610-15)
(KRC-281RG only)
SCREW SET
(N99-1632-05)
(KRC-281RG only)
AUD
1
23456
CLK
ATT
SRC
PWR
OFF
SCAN RDM REP T.C/D.SCN M.RDM
LOUD
DISC
HIGH POWER
40Wx40Wx4
MENU
FM
AM
FF
REW
PR OG
VOL ADJ NAME SETTI
PTY
AUD
1
23456
CLK
ATT
SRC
PWR
OFF
SCAN RDM REP T.C/D.SCN M.RDM
LOUD
DISC
HIGH POWER
40Wx40Wx4
MENU
FM
AM
FF
REW
PR OG
VOL ADJ NAME SETTI
PTY
AUD
1
23456
CLK
ATT
SRC
PWR
OFF
SCAN RDM REP T.C/D.SCN M.RDM
LOUD
DISC
HIGH POWER
40Wx40Wx4
MENU
FM
AM
FF
REW
PR OG
VOL ADJ NAME SETTI
PTY
AUD
1
23456
CLK
ATT
SRC
PWR
OFF
T.CALL
LOUD
HIGH POWER
40Wx40Wx4
MENU
FM
AM
FF
REW
PR OG
VOL ADJTI
PTY
AUD
1
23456
CLK
ATT
SRC
PWR
OFF
T.C/ALL
LOUD
HIGH POWER
40Wx40Wx4
MENU
FM
AM
FF
REW
PR OG
VOL ADJTI
PTY
KRC-279RA/RG/RYA/RYG (E)
KRC-281RG (M)
(KRC-281RG only)
40%
KRC-15R,179R,25R,279R,281R
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
CASSETTE MECHA.
IC5
1 Lch
2 Rch
PRE OUT
IC2
IC4
IC3
SP OUT
REAR
J4
PAN IN SW
ACC DET.
P-CONT.
J2
J5
IC1
FRONT-END
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
Q54-578VQ58-61
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
HD1
L/R
55.6mV
B.U.5V
SW5V
8V
B.U.5V
AM: 170mV
FM: 213mV
TAPE
PACK IN
(FF/REW)
AMP. MUTE
FF/REW
B.U.5V
R QUAL
R CLK
R DATA
SW5V
MP OUT
QUAL
AFC
NOISE
B.U.5V
ILLUMI.
L CE
(X13)
M
KRC-15R,179R,25R,279R,281R (E,M)
A1
TEL DET
D380
5V
R205
CONTENTS / BLOCK DIAGRAM
CONTENTS
CONTENTS / BLOCK DIAGRAM...............................2
COMPONENT DESCRIPTION...................................3
MICROCOMPUTER'S TERMINAL DESCRIPTION ...4
TEST MODE...............................................................6
ADJUSTMENT............................................................7
PARTS DESCRIPTIONS............................................8
BLOCK DIAGRAM
PC BOARD.................................................................9
SCHEMATIC DIAGRAM...........................................13
EXPLODED VIEW....................................................18
PARTS LIST .............................................................21
SPECIFICATIONS......................................Back cover
2
KRC-15R,179R,25R,279R,281R
COMPONENT DESCRIPTION
SYNTHESIZER UNIT (X14-656x-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-15R,179R,25R,279R,281R
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-15R,179R,25R,279R,281R
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-15R,179R,25R,279R,281R
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 fullfront/full-rear each by pressing the "Track UP" / "Track DOWN" keys.
• Sound coordination doesn't appear for the feed.
TEST MODE
6
KRC-15R,179R,25R,279R,281R
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
überprüfen. 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
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