CASSETTE RECEIVER
KRC-13RG
SERVICE MANUAL
© 2000-1 PRINTED IN KOREA
B51-7587-00 (K) 2204
KRC-178RA/RG/RYA/RYG
KRC-23RA/RG
ANTENNA ADAPTOR
(T90-0523-05)
(Except KRC-280RG)
KRC-278RA/RG/RYA/RYG
KRC-280RG
KRC-278R
CD/MD-CHANGER CONTROL
KRC-23R
CD/MD-CHANGER CONTROL
KRC-13R
KRC-178R
KRC-280R
CD/MD-CHANGER CONTROL
KRC-13RG (E)
KRC-178RA/RG/RYA/RYG (E)
KRC-23RA/RG (E)
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.)
STAY
(J54-0606-04)
SCREW SET
(N99-1610-15)
(KRC-280RG only)
SCREW SET
(N99-1632-05)
(KRC-280RG only)
AUD
1
23
456
CLK
ATT
SRC
PWR
OFF
SCAN
RDM
REP
T.C/D.SCN
M.RDM
LOUD
DISC
MENU
FM
AM
FF
REW
PR
OG
VOL ADJ
NAME SET
TI
PTY
AUD
1
23
456
CLK
ATT
SRC
PWR
OFF
SCAN
RDM
REP
T.C/D.SCN
M.RDM
LOUD
DISC
MENU
FM
AM
FF
REW
PR
OG
VOL ADJ
NAME SET
TI
PTY
AUD
1
23
456
CLK
ATT
SRC
PWR
OFF
SCAN
RDM
REP
T.C/D.SCN
M.RDM
LOUD
DISC
MENU
FM
AM
FF
REW
PR
OG
VOL ADJ
NAME SET
TI
PTY
AUD
1
23
456
CLK
ATT
SRC
PWR
OFF
T.CALL
LOUD
MENU
FM
AM
FF
REW
PR
OG
VOL ADJ
TI
PTY
AUD
1
23
456
CLK
ATT
SRC
PWR
OFF
T.C/ALL
LOUD
MENU
FM
AM
FF
REW
PR
OG
VOL ADJ
TI
PTY
KRC-278RA/RG/RYA/RYG (E)
KRC-280RG (M)
(KRC-280RG only)
40%
KRC-13R,178R,23R,278R,280R
2
BLOCK
DIAGRAM
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
ACC DET.
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
Q49
Q50
Q350-353
Q353
P-CON.SW
Q54-57
8V
Q58-61
ILLUMI.
B.U.5V
Q51,52
SYSTEM u-COM
S1
S2
S3
P-CONT.
CD-CH
RST SW
Q301
D1-15
PL1,2
ANT.
TEL MUTE
DECODER
RDS
IC7
Q501,502
MP SW
40W
RESET
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
P
ANEL
RESET
L
CLK
L
D
ATA
S
L
D
ATA
L
FWD/REV
M
OTO
R
CH
CON
D
ATA
H
D
ATA
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
BU5V
8V
B.U.
CHRST
S
MUTE
8
5
10
B.U.5V
AM+B
VDD 5V
P
A
CK
IN
L
RES
PHONE
CHMUTE
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
R
55.6mV
BU5V
SW5V
8V
B.U.5V
AM: 170mV
FM: 213mV
L
PACK IN
(FF/REW)
AMP. MUTE
FF/REW
BU5V
R QUAL
R CLK
R DATA
SW5V
MP OUT
QUAL
AFC
NOISE
BU5V
ILL
L
CE
(X13)
M
KRC-13R,178R,23R,278R,280R (E,E,E,E,M)
A1
SYNTHESIZER UNIT (X14-613x-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.
IC6
RESET
Resets power supply.
IC7
RDS DECODER
Decodes RDS signal.
Q49
ACC DETECTION SW
Works when ACC operation stops.
Q50
BACK-UP DETECTION SW
Works when the back-up voltage comes less than 9.2V.
Q51,52
BACK-UP 5V DRIVER
Works when the back-up works.
Q53
P.ON 5V SW
Works when the power comes.
Q54,55
8V SW
Works when the power comes.
Q56,57
8V DRIVER
Works when the power comes.
Q58,59
ILLUMINATION +B SW
Works when the power comes.
Q60,61
ILLUMINATION +B DRIVER
Works when the power comes.
Q150
ELECTRIC VOLUME MUTE SW
Works when the back-up voltage detection or the changer mute or
µ-com mute works.
Q151
SVR FORCED DISCHARGE SW
Works when the amplifier mute works.
Q153
PRE OUT MUTE SW
Works when the back-up voltage detection or the changer mute or
µ-com mute works.
Q201
FM +B SW
Works when FM mode is being selected.
Q203
AM +B SW
Works when AM mode is being selected.
Q260
MOTOR +B SW
Works when TAPE mode is being selected.
Q261
MOTOR +B DRIVER
Works when Q260 works.
Q301
CHANGER RESET SW
Works when power supply is being reset and IC6 works.
Q320
PANEL 5V SW
Works when the back-up works and panel is on the unit.
Q350
P-CON. DRIVER
Stops during POWER OFF and ALL OFF modes.
Q351
P-CON. PROTECTION SW
Works when P-CON is being short-circuited on GND.
Q352
P-CON. PROTECTION INHIBIT SW Inhibits protection SW function when P-CON works momentary.
Q353
P-CON. SW
Stops during POWER OFF and ALL OFF modes.
Q450,451
PRE OUT MUTE SW
Works when the back-up voltage detection or the changer mute or
µ-com mute works.
Q500
AUDIO OUT BUFFER
For RDS decorder (IC7).
Q501,502
AFC TIME CONSTANT SW
Works when receiving FM signal. Stops when seeking FM signal.
Q503
NOISE BUFFER
For noise level detection.
KRC-13R,178R,23R,278R,280R
3
COMPONENT DESCRIPTION
KRC-13R,178R,23R,278R,280R
4
CIRCUIT DESCRIPTION
(X14-) IC1 :
µ-COM
PORT No.
PORT NAME
I/O
FUNCTION
OPERATING CONDITION
1
PANEL
I
Panel on/off detection.
"L" : Panel on.
"H" : Panel off.
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 signal.
-
7
AVREF 1
I
Reference voltage.
-
8
IC2 SEL 1
I
To GND.
-
9
IC2 SEL 0
I
To GND.
-
10
-
-
No connection.
-
11
L DATA L
I
LCD driver data.
-
12
L DATA S
O
LCD driver data.
-
13
L CLK
O
LCD driver clock.
-
14,15
-
-
No connection.
-
16
DATA C
I
Changer data.
-
17
DATA H
O
Changer data.
-
18
CH CLK
I
Changer clock.
-
19-26
-
-
No connection.
-
27
MOTOR
O
Cassette motor on/off.
-
28
FF/REW
I
FF/REW.
-
29-31
-
-
No connection.
-
32
SD
I
Tuner signal detection.
"H" : Tuner signal exists.
"L" : Tuner signal does not exist.
33
VSS 1
-
GND.
-
34
-
-
No connection.
-
35
PLL CLK
O
PLL clock.
-
36
PLL DATA
I/O PLL data.
-
37
AM+B
O
AM power supply.
-
38
FM+B
O
FM power supply.
-
39
IC2 DATA
I/O E-volume data.
-
40
IC2 CLK
O
E-volume clock.
-
41
AFC
O
FM noise detection time constant switch.
-
42
MUTE
O
Mute control.
-
43
AMP MUTE
O
Power IC (IC4) mute.
-
44
-
-
No connection.
-
45
CH CON
O
Changer control.
-
46
REC H
O
Request to head unit.
-
47
-
-
No connection.
-
48
SVR
O
Power IC (IC4) discharge control.
-
49
AMP STBY
O
Power IC (IC4) stand-by.
-
50
BEEP
O
Buzzer.
-
51,52
-
-
No connection.
-
53
P.CONT
O
Power control on/off.
-
54
ACC DET
I
ACC detection.
-
55
B.U. DET
I
Back-up detection.
-
56
P.ON
O
Power on/pff.
-
57
ILL
O
Illumination on/off.
-
58
FWD/REV
I
FWD/REV detection.
-
59
-
-
No connection.
-
60
RESET
I
System reset.
-
61
SEL 1
I
Destination switch.
-
62
R CLK
I
RDS clock.
-
63
REQ C
I
Request from changer.
-
64
PACK IN
I
Cassette tape Pack-in detection.
65
KEY-REQ
I
Key detection.
-
-
66
SEL 0
I
Destination switch.
-
67
VSS 0
-
GND.
-
68
VDD 1
-
VDD.
-
69
X2
-
Main system clock.
-
70
X1
-
Main system clock.
-
71
IC
-
GND.
-
72
XT2
-
No connection.
-
73
XT1
-
VDD.
-
74
VDD 0
-
VDD.
-
75
AVREF 0
I
Reference voltage.
-
76
S METER
I
Signal meter.
-
77
PHONE
I
Tel/Navi mute.
Tel mute : Less than 1V.
Navi mute : More than 2.5V.
78
NOISE
I
FM noise detection.
-
79
AV CONT
O
A/D refernce voltage control.
-
80
--
No connection.
-
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-13R,178R,23R,278R,280R