Kenwood KRC-208-S, KRC-218, KRC-268, KRC-28-MR, KRC-288 Service manual
CASSETTE RECEIVER
KRC-208S/218
SERVICE MANUAL
© 2000-1 PRINTED IN KOREA
B51-7586-00 (K) 1787
KRC-268/288
KRC-28MR
KRC-28MR (K)
PLASTIC CABINET ASSY
(A02-1486-13)
LEVER
(D10-3031-04) x2
MOUNTING HARDWARE ASSY
(J21-9491-03)
DC CORD
(E30-xxxx-xx)
(Refer to the parts list.)
CD/MD-CHANGER CONTROL
KRC-208S
CD/MD-CHANGER CONTROL
KRC-28MR
KRC-268
KRC-208S (K)
KRC-218 (K)
KRC-268 (M)
STAY
(J54-0606-04)
SCREW SET
(N99-1610-15)
(Except KRC-28MR)
SCREW SET
(N99-1632-05)
KRC-218
CD/MD-CHANGER CONTROL
KRC-288
KRC-288 (M)
AUD
1
23456
CLK
ATT
SRC
PWR
OFF
AME ADJAUTO
SCAN RDM REP T.C/D.SCN M.RDM
LOUD
DISC
CRSC
A.ADJ
FM
AM
FF
REW
PR OG
AUD
1
23456
CLK
ATT
SRC
PWR
OFF
AME ADJAUTO
SCAN RDM REP T.C/D.SCN M.RDM
LOUD
DISC
CRSC
A.ADJ
FM
AM
FF
REW
PR OG
AUD
1
23456
CLK
ATT
SRC
PWR
OFF
AME ADJAUTO
T.CALL
LOUD
CRSC
A.ADJ
FM
AM
FF
REW
PR OG
AUD
1
23456
CLK
ATT
SRC
PWR
OFF
AME ADJAUTO
T.CALL
LOUD
CRSC
A.ADJ
FM
AM
FF
REW
PR OG
AUD
1
23456
CLK
ATT
SRC
PWR
OFF
AME ADJAUTO
SCAN RDM REP T.C/D.SCN M.RDM
LOUD
DISC
CRSC
A.ADJ
FM
AM
FF
REW
PR OG
40%
2
IC1
KEY
PANEL 5V SW
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
1 Lch
2 Rch
PRE OUT
IC2
IC4
IC3
SP OUT
REAR
J4
RESET SW
PAN IN SW
ANT-CONT.
P-CONT.
J2
J5
IC1
FRONT-END
J1
FM+B
Q201
AM+B
Q203
AM BPF
FM BPF
C154,157,R206
C153,156,R207
Q320
Q450,451
Q370,371
Q50
Q350-353
Q353
P-CON.SW
Q54-57
COM+B
Q58-61
ILLUMI.
B.U.5V
Q51,52
SYSTEM u-COM
S1
S2
S3
P-CONT.
CHANGER
RST SW
Q301
D1-15
PL1,2
ANT.
ANT-CONT.
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
SW5V
ACC DET
B.U. DET
SCL
MUTE
SDA
P. CON
PANEL
HOLD
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
TAPE
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.
CHRST
S MUTE
8
4
10
B.U.5V
AM+B
VDD 5V
PACK IN
L CE
ANT CON
CHMUTE
BEEP
SVR
AMP. STBY
SVR
AC GND (BEEP)
Lch Lch
Rch
Lch
1200mV
TAPE :1681mV
CD/MD-CH :3529mV
AM :546mV
FM :1781mV
8V
RF GND
OSC GND
IF2 +B
AUDIO OUT
8V
S-METER
SD
PLL CLK
PLL DATA
M1
HD1
R
55.6mV
BU5V
SW5V
8V
B.U.5V
AM: 170mV
FM: 400mV
L
PACK IN
(FF/REW)
AMP. MUTE
FF/REW
BU5V
ILL
(X13)
M
KRC-208S/218,268/288,28MR (K/K,M/M,K)
A1
KRC-208S/218,268/288,28MR
BLOCK DIAGRAM
SYNTHESIZER UNIT (X14-614x-xx)
REF. No.
FUNCTION OPERATION
IC1 SYSTEM µ-COM Controls system.
IC2 ELECTRIC VOLUME Controls sound volume. Selects each source.
IC3 MUTE Controls each mute output.
IC4 POWER IC Amplifies power so that the speaker can drive audio signal.
IC5 EQUALIZER AMPLIFIER Equalizer amplifier for cassette tape sound.
Q50 BACK-UP DETECTION Stops when the back-up voltage comes less than 9.2V.
Q51,52 BACK-UP 5V AVR Works when the back-up works.
Q53 P.ON DRIVER Works when the power comes.
Q54,55 COM+B SW Works when 5V comes.
Q56,57 COM+B AVR Works when Q54 and Q55 work.
Q58,59 ILLUMINATION +B SW Works when the base level of Q58 comes "H".
Q60,61 ILLUMINATION +B AVR Works when Q58 and Q59 work.
Q150 ELECTRIC VOLUME MUTE SW Works when the base level comes "H".
Q151 SVR DISCHARGE SW Works when the base level comes "H".
Q153 PRE MUTE DRIVER Works when the base level comes "L".
Q200 FM +B SW Works when the base level comes "H" in FM mode.
Q201 FM +B DRIVER Works when Q200 works.
Q202 AM +B SW Works when the base level comes "H" in AM mode.
Q203 AM +B DRIVER Works when Q203 works.
Q260 MOTOR +B SW Works when the base level comes "H" in the tape mode.
Q261 MOTOR +B DRIVER Works when Q260 works.
Q301 CHANGER RESET SW Works when the base level comes "L".
Q320 PANEL 5V SW Works when the base level comes "L".
Q350 P-CON. DRIVER Works when Q353 works.
Q351,352 P-CON. PROTECTION Works when P-CON output voltage goes down.
Q353 P-CON. SW Works when the base level comes "H".
Q370 ANTENNA CONTROL DRIVER Works when Q371 works.
Q371 ANTENNA CONTROL SW Works when the base level comes "H" in the tuner mode.
Q450,451 PRE MUTE SW Works when Q153 works.
KRC-208S/218,268/288,28MR
COMPONENT DESCRIPTION
3
KRC-208S/218,268/288,28MR
(X14-) IC1 : µ-COM
PORT No. PORT NAME I/O FUNCTION OPERATING CONDITION
1 XIN I µ-com clock. (4.5MHz) 2 GND -
GND.
-
3
L DATA L I
LCD driver data.
-
4
L DATA S
O
LCD driver data.
-
5
L CLK O
LCD driver clock.
-
6 L CE O
LCD driver chip enable.
-
7
SDA I/O E-volume data.
-
8 PLL DATA I/O Tuner data.
-
9
PLL CLK O Tuner clock.
-
10 SD I Tuner signal detection.
"H" : Tuner signal exists.
"L" : Tuner signal does not exist.
11
DATA C I Changer data.
-
12 DATA H
O
Head unit data.
-
13
CH CLK
I/O Changer clock.
-
14 - - No connection.
-
15
MOTOR O Mechanism motor.
-
16
SCL O
E-volume clock.
-
17-24
- - No connection.
-
25 AM+B
O
AM power supply.
-
26
FM+B O FM power supply.
-
27
PACK IN
I Cassette tape pack-in.
"L" : Pack in. "H" : Ejection.
28
FF/REW
I FF/REW signal.
"L" : FF/REW. "H" : Play.
29,30 GND - GND.
-
31
VDD - VDD.
-
32
REQ C
I
Request from changer.
-
33
MUTE O Mute.
-
34 CH CON
O
Changer control.
-
35
REQ H
O Request to head unit.
-
36 SVR O Power IC (IC4) discharge control.
-
37
AMP STBY O Power IC (IC4) stand-by.
-
38
AMP MUTE
O Power IC (IC4) mute.
-
39
P CON O P.CON for external amplifier.
-
40 ANT. CON
O
Power antenna.
-
41 SW5
O
Circumambient circuit power supply control.
-
42
ILL O Illumination.
-
43 - - No connection.
-
44
BEEP O
Buzzer. (2KHz)
-
45-47
- - No connection.
-
48
ROLL OFF
I Destination switch.
-
49
N.CAN
I Destination switch.
-
50
SEL1
I
Destination switch.
-
51
SEL2 I
Destination switch.
-
52
--
No connection.
-
53
EQ MUTE
O Tape equalizer mute.
-
54
FWD/REV
I FWD/REV.
-
55 - - No connection.
-
56
REMO
I
Remote control.
-
57-60
- - No connection.
-
61
ACC DET I ACC detection.
-
62
BU DET
I Back-up detection.
-
63
S METER I Tuner signal meter.
-
64
PANEL
I
Panel on/off.
"L" : Panel on. "H" : Panel off.
65,66
GND - GND.
-
67
HOLD
I Clock stop.
-
68
VDD - VDD.
-
69,70
GND
-
GND.
-
71,72
- - No connection.
-
73
VDD - VDD.
-
74,75
GND - GND.
-
76
VSS
- GND.
-
77,78
- - No connection.
-
79
GND - GND.
-
80
XOUT O
µ-com clock. (4.5MHz)
-
CIRCUIT DESCRIPTION
4
KRC-208S/218,268/288,28MR
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 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.
5
KRC-208S/218,268/288,28MR
(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/EINSTELLUNGEN (MECHA.)
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)
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)
6
Loading...