KENWOOD KRC878R Service Manual

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Service Manual for KENWOOD KRC878R, downloadable as a PDF file.

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KRC-PS978R
KRC-878R
KRC-778R
//
.
B.S/
MTL/
DISP
B.S/
MTL/
DISP
KRC-778R/RV/RY/RYV,
878R, PS978R
CASSETTE RECEIVER
SERVICE MANUAL
C
2000-2 PRINTED IN KOREA
B51-7589-00 ( K ) 1889
KRC-PS978R
KRC-878R
KRC-778R
Front glass
(B10-3095-01)
Escutcheon assy
(B07-2146-03)
Panel assy
(A64-1854-02)
Front glass
(B10-3096-01)
Escutcheon assy
(B07-2139-03)
Front glass
KRC-778R/RY :
(B10-3097-01)
KRC-778RV/RYV :
(B10-3098-01)
Escutcheon assy
(B07-2139-03)
Panel assy
(A64-1855-02)
Panel assy
KRC-778R/RY :
(A64-1856-02)
KRC-778RV/RYV :
(A64-1952-02)
Torsion coil spring
(G01-2924-04)
Lever
(D10-4301-14)
(D10-4302-14)
Antenna adaptor
(T90-0523-05)
Remote controller assy
(A70-0886-15)
Screw set
(N99-1683-05)
Remote controller assy
(A70-0874-05)
Mounting hardware assy
(J21-9491-03)
DC cord
KRC-PS978R,878R,778R/RY :
(E30-4788-05)
KRC-778RV/RYV :
(E30-4789-05)
Plastic cabinet assy
(A02-1489-03)
The CASSETTE MECHANISM OPERATION DESCRIPTION is the same model D40-1122-05.
Please refer to the service manual for model D40-1122-05(B51-7452-00).
40%
background image
KRC-PS978R
KRC-878R
KRC-778R
//
.
B.S/
MTL/
DISP
B.S/
MTL/
DISP
KRC-778R/RV/RY/RYV,
878R, PS978R
CASSETTE RECEIVER
SERVICE MANUAL
C
2000-2 PRINTED IN KOREA
B51-7589-00 ( K ) 1889
KRC-PS978R
KRC-878R
KRC-778R
Front glass
(B10-3095-01)
Escutcheon assy
(B07-2146-03)
Panel assy
(A64-1854-02)
Front glass
(B10-3096-01)
Escutcheon assy
(B07-2139-03)
Front glass
KRC-778R/RY :
(B10-3097-01)
KRC-778RV/RYV :
(B10-3098-01)
Escutcheon assy
(B07-2139-03)
Panel assy
(A64-1855-02)
Panel assy
KRC-778R/RY :
(A64-1856-02)
KRC-778RV/RYV :
(A64-1952-02)
Torsion coil spring
(G01-2924-04)
Lever
(D10-4301-14)
(D10-4302-14)
Antenna adaptor
(T90-0523-05)
Remote controller assy
(A70-0886-15)
Screw set
(N99-1683-05)
Remote controller assy
(A70-0874-05)
Mounting hardware assy
(J21-9491-03)
DC cord
KRC-PS978R,878R,778R/RY :
(E30-4788-05)
KRC-778RV/RYV :
(E30-4789-05)
Plastic cabinet assy
(A02-1489-03)
The CASSETTE MECHANISM OPERATION DESCRIPTION is the same model D40-1122-05.
Please refer to the service manual for model D40-1122-05(B51-7452-00).
40%
background image
KRC-778R/R
V/R
Y/R
YV
,878R,PS978R
2
BLOCK
DIAGRAM
FM+B
AM+B
E2PROM
DIMMER
TEL-MUTE
ACC DET.
SRM
MECHA
BU DET.
DRIVER
LCD
SUB
DRIVER
A 8V
SUB MOT
SW14V
ILL AVR
SW5V
B.U.5V
P CON
DRIVER
SYSTEM
E'S
POWER IC
IC4
IC14
Q32
Q23
Q21,22
Q28,29,31
Q25
Q24
SYSTEM u-COM
IC1
Q18-20
Q37,38
MECH
CHANGER
IC10
IC1,2
Q35,36
Q33,40,44
Q1-6
IC5
IC2
F/E
MECHA
DET.
IC13
E-VOL
Q87,89
Q86,88
SP-OUT
ILL
TEL-MUTE
ACC
P CON
BACK UP
RDS DECODER
IC11
AMP
IC12
NOISE
REMO
IC3
G/A SW
VLCD
4.5V PRE OUT
EXT. AMP CONT
Q39
EXT. AMP CONT
AVR
RST SW
RESET
IC15
POSISTOR
BACK
LIGHT
Q8
LCD
MAIN MOT
AVR
Q41,42
DC/DC
IC6
(FOR 4.5V PRE)
4.5V PRE AMP
Q26,27
CON
ANT
ANT CON
IC6
1.8V PRE OUT
WIDE/
NARROW
Q82
N.C.
MPX
MUTE
MUTE LOGIC
P-5V
Q57-62
MOT
SRM
DIMMER
MD-
CD-
CASSETTE
Depeds on the model.
Refer to the parts list.
PLL CLK
CHANGER
F/R
TAPE IN
MODE 3
MODE 1
R REEL
MTL ON/OFF
DOLBY ON/OFF
MODE 2
F REEL
MS MODE
MUTE
DOLBY B/C
CH CLK
CH CON
DATAC
REQ H
CH RST
REQ C
DATAH
TAPE
AM
FM
MUTE
RESET
SRM
SW1
SRM
DET
SRM
SW2
SUB
MOT1
RCLK
QUAL
R
D
ATA
FM+B
SDA
SCK
A8V
SW5V
PLL DATA
PLL CE
FM SD
FSD OUT
REQUEST
RDS OUT
SW5V
FM+B
AM+B
S METER
FM SD
NARROW
IF MODE
PLL CE
NOISE
CH MUTE
BACK UP
6
13
8
SW5V
S METER
P MUTE
EXT. AMP CONT
AC GND
DIMMER
PHONE
ACC DET
P CON
BU DET
BEEP
SW5
P-ON
L
CLK
L
D
ATA
S
L
C
E
L
D
ATA
L
LOCK
SW
DIMMER
REMO
BU5V
160mV
1200mV
388mV
2
ILL
ON
213mV
MS OUT
MODE 1
MODE 3
TAPE IN
MODE 2
DOLBY ON/OFF
DOLBY B/C
MTL ON/OFF
MS MODE
R REEL
F REEL
F/R
MUTE
MS OUT
400mV: (K) TYPE
: (E) TYPE
3
24
CASS/SRM
SUB
MOT2
SUB
MOT3
MOTOR
B
B
7
ANT CON
MUTE
+B
-B
CH
(K) TYPE
(E) TYPE
AM
3600mV
3600mV
FM
855mV
600mV
TAPE
1372mV
1800mV
1800mV
1800mV
(K) TYPE
(E) TYPE
1715mV
2250mV
4500mV
1069mV
CH
FM
AM
TAPE
4500mV
2250mV
2250mV
750mV
SUB+
SUB-
MOT+B
FM
AM
IF SELECT
2
SW5V
AFC
B.U.5V
B.U.5V
BACK UP
SW5V
PRE MUTE
S MUTE
P-5V
SW5V B.U.5V
A 8V
2
2
2
ILL
REQ H
CH MUTE
CH RST
CH CON
REQ C
DATAH
DATAC
CH CLK
IF MODE
WIDE
PLL DATA
PLL CLK
SW5V
SUB-
SUB+
MOT+B
SW 5V
A 8V
SCK
SDA
SDA
SCK
(X13- )
KRC-X858
KRC-778R/RY
KRC-PS988R
KRC-708
KRC-PS978R
KRC-888
KRC-778RV/RYV
KRC-878R
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UPD784217GC103(105) (IC1: X14-618X-XX)
System MicroComputer
Pin
Pin Name
Signal Name
I/O
Purpose
Operation Description
1
P120/RTP0
CHCON
O
Changer control terminal.
ON:Hi, OFF:Lo
2
P121/RTP1
CH_MUTE
I
Muting input to changer.
ON:Hi, OFF:Lo
3
P122/RTP2
REQH
O
Handshake request to changer.
4
P123/RTP3
DIMMER
I
Small detection.
DIMMER ON:Lo, OFF:Hi
5
P124/RTP4
MOTER
O
Cassette mechanism main motor
output.
Active; Hi.
6
P125/RTP5
NC
O
7
P126/RTP6
NC
O
8
P127/RTP7
NC
O
9
Vdd
Vdd
-
Positive power supply.
10
X2
X2
-
Main clock connection.
11
X1
X1
-
Main clock connection.
12
Vss
Vss
-
GND terminal.
13
XT2
XT2
-
Sub-clock connection.
14
XT1
XT1
-
Sub-clock connection.
15
RESET
RESET
I
Reset input.
Active: Lo.
16
P00/INTP0
CH_RST
O
Reset output to changer.
Active: Hi.
17
P01/INTP1
R_CLK
I
RDS clock input.
18
P02/INTP2/NMI
REQC
I
Handshake request from changer.
19
P03/INTP3
KEY REQ
I
20
P04/INTP4
SUB_MOTOR3
O
Sub-motor output. 3
21
P05/INTP5
SUB_MOTOR2
O
Sub-motor output. 2
22
P06/INTP6
SUB_MOTOR1
O
Sub-motor output. 1
23
AVdd
Avdd
-
A/D analog power supply.
24
AVref0
AVref0
-
A/D reference voltage input.
25
P10/ANI0
PHONE
I
Phone detection.
1 V or less: TEL MUTE
/2.5 V or more: NAVI MUTE.
26
P11/ANI1
SRM_SW1
I
SRM position detection.
Open: Hi.
27
P12/ANI2
NOISE
I
FM noise detection.
28
P13/ANI3
SMETER
I
FM S meter detection.
29
P14/ANI4
F_REEL
I
Cassette mechanism reel pulse input
(FWD).
30
P15/ANI5
R_REEL
I
Cassette mechanism reel pulse input
(REV).
31
P16/ANI6
N.C.
I
32
P17/ANI7
N.C.
I
33
AVss
AVss
-
A/D GND terminal.
34
P130/ANO0
EXT_AMP
O
External amp control.
L 40mS:Bass boost OFF
L 70mS:Bass boost LOW
L 100mS:Bass boost Hi
35
P131/ANO1
IF_MODE
I
IF status detection for K2I.
Hi = WIDE, Lo = NARROW
36
AVref1
AVref1
-
D/A reference voltage input.
37
P70/RxD2/SI2
DATAC
I
Data line from changer.
38
P71/TxD2/SO2
DATAH
O
Data line to changer.
39
P72/ASCK2/SCK2 CH_CLK
I/O
Clock line with changer.
40
P20/RxD1/SI1
L_DATAL
I
Data line from LCD driver.
41
P21/TxD1/SO1
L_DATAS
O
Data line to LCD driver.
42
P22/ASCK1/SCK1 L_CLK
O
Clock line to LCD driver.
43
P23/PCL
DIMMER
O
Dimmer control output.
44
P24/BUZ
BEEP
O
Beep output.
Active: Hi.
45
P25/SI0
PLL_CE
O
CE to PLL.
46
P26/SO0
PLL_DATA
I/O
Data input/output with PLL.
47
P27/SCK0
PLL_CLK
O
Clock output to PLL.
48
P80/A0
ILL_ON
O
ILL ON
ILL ON : Hi
49
P81/A1
PANEL_5V
O
5V power supply control for LCD
driver.
Active: Lo.
50
P82/A2
L_CE
O
CE terminal to LCD driver
51
P83/A3
LOCK_SW
I
Panel lock SW detection terminal.
Lock SW ON : Lo
KRC-778R/RV/RY/RYV,878R,PS978R
3
MICROCOMPUTER TERMINAL DESCRIPTION
background image
UPD784217GC103(105) (IC1: X14-618X-XX)
System MicroComputer
Pin
Pin Name
Signal Name
I/O
Purpose
Operation Description
52
P84/A4
WIDE
O
K2I Forced Wide output.
H:Forced Wide
53
P85/A5
NARROW
I/O
K2I Forced Narrow output.
H:Forced Narrow
54
P86/A6
AFC
I
Noise detection time constant SW
During reception: Hi
/During search: Lo.
55
P87/A7
SRM_SW2
I
SRM eject position detection.
EJECT:Hi
56
P40/AD0
QUAL
I
RDS reception quality.
57
P41/AD1
R_DATA
I
RDS data input.
58
P42/AD2
SRM_DET
I
SRM mechanism detection.
Detected: Lo /Not detected: Hi.
59
P43/AD3
FM_SD
I
FM SD input.
Station detected: Hi
/Not detected: Lo.
60
P44/AD4
N.C.
O
61
P45/AD5
MUSIC
I
Blank detection input.
Music detected: Lo
/Music not detected: Hi.
62
P46/AD6
B/C
O
Dolby B/C switching.
B = Lo, C = Hi
63
P47/AD7
Dolby
O
Dolby output.
ON : Hi, OFF : Lo
64
P50/A8
EQ_MUTE
O
EQ muting output.
During play: Lo /FF or REW:
65
P51/A9
MTL
O
Metal output.
NOMAL : Hi, METAL : Lo
66
P52/A10
F/R
O
Tape EQ input switching.
FWD:Lo, REW:Hi
67
P53/A11
MSC
O
Blank detection time constant
switching.
During play: Hi /FF or REW:
Lo.
68
P54/A12
MODE3
I
Cassette mechanism mode detection.
69
P55/A13
MODE1
I
Cassette mechanism mode detection.
70
P56/A14
MODE2
I
Cassette mechanism mode detection.
71
P57/A15
PACK_DET
I
Cassette mechanism pack detection.
Pack detected: Lo.
72
Vss
GND
-
GND terminal.
73
P60/A16
TYPE0
I
Destination type terminal 0.
74
P61/A17
TYPE1
I
Destination type terminal 1.
75
P62/A18
TYPE2
I
Destination type terminal 2.
76
P63/A19
ST_TYPE0
I
IC2 Ver.3 destination type terminal 0.
77
P64/RD
ST_TYPE1
I
IC2 Ver.3 destination type terminal 1.
78
P65/WR
N.C.
O
Not used.
79
P66/WAIT
N.C.
O
Not used.
80
P67/ASTB
N.C.
O
Not used.
81
Vdd
Vdd
-
B.U.5V
82
P100/TI5/TO5
SVR
O
SVR discharge control.
POWER OFF:Hi
83
P101/TI6/TO6
PREMUTE
O
PRE mute.
Active: Lo.
84
P102/TI7/TO7
PMUTE
O
Power IC muting.
P IC ON : Hi
85
P103/TI8/TO8
CASS/SRM
O
Cassette mechanism / SRM
mechanism voltage SW terminal.
C mech.:Hi, SRM mech.:Lo
86
P30/TO0
ANT_CON
O
Antenna control.
Active: Hi.
87
P31/TO1
AM+B
O
AM power supply.
Active: Hi.
88
P32/TO2
FM+B
O
FM power supply.
Active: Hi.
89
P33/TI1
P_CON
O
Power control.
Active: Hi.
90
P34/TI2
ACC_DET
I
Acc detection.
Acc OFF:Hi.
91
P35/TI00
REMO
I
Remote control input.
92
P36/TI01
P_ON
O
Power supply control.
POWER ON:Hi
93
P37
BU_DET
I
Momentary power down detection.
Power down: Hi.
94
TEST
TEST
-
Test terminal.
95
P90
IC2_SDA
I/O
IC2, IC5 and EEPROM data line.
96
P91
IC2_SCK
O
IC2, IC5 and EEPROM clock line.
97
P92
MUTE
O
Muting terminal.
OPEN:MUTE ON
98
P93
SW5V
O
5 V power supply.
Lo=SW5 ON
99
P94
N.C.
O
Not used.
100 P95
N.C.
O
Not used.
KRC-778R/RV/RY/RYV,878R,PS978R
4
MICROCOMPUTER TERMINAL DESCRIPTION
background image
KRC-778R/RV/RY/RYV,878R,PS978R
5
TEST MODE
2000 MODEL
(1) How to enter the test mode
Reset the set while holding the FM and preset 6 keys
depressed.
All indications light up at the moment the test mode
starts.
(2) How to exit from the test mode
Reset the set while holding the preset 6 key.
(Note) The test mode is not canceled by turning Acc OFF,
turning power OFF or causing momentary power down.
(3) FM S meter voltage adjustment
1. Enter the test mode.
2. While holding the preset 1 key depressed, press and
hold the preset 6 key.
3. "ADJ OK" is displayed when the result is OK or "ADJ
NG" is displayed when it is No Good.
(4) AM SD voltage write
1. Enter the test mode.
2. While holding the preset 1 key depressed, press and
hold the preset 6 key to write the SD voltage data.
(5) Forced Auto/Manual switching of K2I
Press and hold the TI key in the TUNER mode to switch
between AUTO and MANUAL.
The initial status is MANUAL, which is indicated by the
lighting of the TI dots.
(6) Forced Narrow/Wide switching of K2I
Press the preset 6 key in the TUNER mode to switch
between Forced Narrow and Wide.
The initial status is Wide, which is indicated by the light-
ing of the NEWS dot.
(7) TAPE test mode specification
o The blank skip function is initially turned off.
(8) Audio adjustments
o The volume should be set to -10 dB (displayed as "30").
o The bass/treble and balance/fader controls are set to
full boost/full cut and full front/full rear respectively by
single press of the UP/DOWN key.
o The high-pass filter is set to Through/100 Hz/200 Hz by
each press of the UP key, or to 200 Hz/100
Hz/Through by each press of the DOWN key.
(9) Back-up current measurement
When the set is reset while Acc is off (i.e. when the back-
up power is on) or when Acc is turned off in the middle of
test mode, the MUTE pin turns ON in 2 seconds instead
of 15 seconds. (The panel/CD/C/MD mechanism is not
activated at this time.)
(10) Procedure for security code registration after
the E2PROM replacement during servicing
(KRC-888 only)
1. Enter the test mode (see "(1) How to enter the test
mode").
2. Press the SRC key to select ALL OFF.
3. Press and hold the AUDIO key for 1 second to enter the
menu mode.
4. Press the FM/AM key to select "SECURITY".
5. Press and hold the Track UP/DOWN key for 2 seconds.
6. Enter the security code by pressing the preset 1, 2, 3
and 4 keys.
Example: To enter "3510"
- Press preset key "1" 4 times.
- Press preset key "2" 6 times.
- Press preset key "3" 2 times.
- Press preset key "4" 1 time.
7. Press and hold the DISP key for 3 seconds so that
"APPROVED" is displayed.
8. Exit from the test mode (see "(2) How to exit from the
test mode").
(11) Simplified security code clear procedure
(KRC-X858, KRC-708)
1. During the code request mode, while holding the DISP
key depressed, press and hold the Volume UP key for
3 seconds (so that "----" disappears).
2. Enter "KCAR" from the remote control unit. (Same oper-
ation as with the '98 models)
- Press numeric key "5" 2 times and press the Track UP
key (to enter "K").
- Press numeric key "2" 3 times and press the Track UP
key (to enter "C").
- Press numeric key "2" 1 time and press the Track UP
key (to enter "A").
- Press numeric key "7" 2 times and press the Track UP
key (to enter "R").
3. The security is canceled and the set enters the TUNER
mode.
(12.1) MASK key write procedure in production line
(when the E2PROM is in the initial status)
1. While holding the FM and preset 6 keys depressed,
press RESET to enter the test mode.
2. Press and hold the AUDIO key for 1 second to enter
the menu mode.
3. Press the FM or AM key to select "Mask key".
4. Press the Track UP/DOWN key shortly so that
"TRANSMIT1" is displayed.
5. Point the MASK key to the light sensor and press and
hold the key for more than 0.5 second.
6. When "TRANSMIT2" is displayed, press and hold the
MASK key again for more than 0.5 second. Note that
the first and second counter codes are not compared
at this time.
7. The write operation is complete when "APPROVED" is
displayed. At this time, the demonstration mode is set
and the test mode is canceled.
(Note) Similarly to the '98 models, leaving the set for more
than 30 minutes without writing the code causes an
error and turns power off.

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