JVC KS-FX8R User manual

SERVICE MANUAL
CASSETTE RECEIVER
No.49580
Jan. 2001
COPYRIGHT 2001 VICTOR COMPANY OF JAPAN, LTD.
KS-FX8R
KS-FX8R
Area Suffix
E Continental Europe
40Wx4
TP
DISP
RPT
SSM
SCM
MO
RND
789101112
PTY
CD -CH
FM/AM TAPE
/I
ATT
/
DOLBY B NR DAB
RDS
KS-FX8RKS-FX8R
Contents
Safety precaution
Disassembly method
Adjustment method
Description of major ICs
1-2
1-3
1-10
1-14

KS-FX8R
1-2
!Burrs formed during molding may be left over on some parts of the chassis. Therefore,
pay attention to such burrs in the case of preforming repair of this system.
Safety precaution

KS-FX8R
1-3
Press the release switch and remove the front panel
unit in the direction of the arrow.
1.
Disassembly method
Removing the front panel unit
(See Fig.1)
Remove the two screws A attaching the front chassis.
Insert a screwdriver to the two joints aon the left
side of the front chassis, two joints bon the right side
and one joint cfrom upside, then detach the front
chassis toward the front side.
1.
2.
Removing the front chassis (See Fig.2~3)
Remove the three screws B attaching the heat sink
on the left side of the body, and remove the heat
sink.
1.
Removing the heat sink (See Fig.4)
Joint c
Heat sink
Fig.2
Fig.1
Fig. 3
Fig. 4
Front panel unit
Front chassis
A
Front chassis
Joint a
Joint a Joint b
Joint b
BB

KS-FX8R
1-4
Prior to performing the following procedure, remove
the front chassis and the heat sink.
Turn the body upside down.
Insert a screwdriver to the two joints dand two joints
eon both sides of the body and the joint fon the
back of the body, then detach the bottom cover from
the body.
1.
2.
Removing the bottom cover (See Fig.5)
Prior to performing the following procedure, remove
the front chassis, the heat sink and bottom cover.
Remove the five screws C attaching the rear panel
and one screw D attaching the pine jack on the back
of the body.
1.
Removing the rear panel (See Fig.6 )
Prior to performing the following procedure, remove
the front chassis, the heat sink, bottom cover and the
rear panel.
Remove the two screws E attaching the main
amplifier board assembly on the top cover.
Disconnect connector CP401 on the main amplifier
board assembly from the cassette mechanism
assembly.
1.
2.
Removing the main amplifier board assembly
(See Fig.7)
Bottom cover
Fig. 5
Fig. 6
Fig. 7
Main board assembly
Joints d
Joints e
Joint f
CC
C
D
Rear panel
CP401
EE

KS-FX8R
1-5
Prior to performing the following procedure, remove
the front chassis, the heat sink, bottom cover and the
main amplifier board assembly.
Remove the four screws Fattaching the cassette
mechanism assembly from the top cover.
1.
Removing the cassette mechanism assembly
(See Fig.8)
Remove the front panel unit from the main body.
Remove the five screws Gattaching the rear cover
on the back of the front panel unit.
Remove the control switch board from the front panel
unit.
1.
2.
3.
Removing the (LCD & key) control switch
board (See Fig.9 and 10 )
Cassette mechanism assembly
F
FFTop cover
Fig. 8
GG
GG
Fig. 9
Fig. 10
LCD & Key control board
F

KS-FX8R
1-6
For the 6pin wire extending from connector CN402
on the head amplifier board, disconnect it from the
head relay board.
Disconnect the card wire from connector CN403 on
the head amplifier board.
Remove the screw Aattaching the head amplifier
board.
Move the tab aas shown in Fig.2 and remove the
head amplifier board while moving it in the direction
of the arrow.
1.
2.
3.
4.
<Removal of the cassette mechanism>
Removing the head amplifier board.
(See Fig.1 and 2)
Disconnect the 6pin wire from connector CN402 and
the card wire from CN403 on the head amplifier
board (Refer to Fig.1 and 2).
Remove the four screws Bon the bottom of the
cassette mechanism.
1.
2.
Removing the cassette mechanism
assembly (See Fig.1 to 3)
Fig.1
Cassette mechanism ass’y
Head relay
board
6pin
wire
CN402 CN403
CN402
Head amplifier board
Fig.2
Tab a
Head amplifier board
Fig.3
Cassette mechanism ass’y
B
B
A
Head amplifier board
CN403

KS-FX8R
1-7
Unsolder the soldering bon the head relay board.
Remove the screw Cattaching the head relay board.
Remove the head relay board in the direction of the
arrow while releasing the two joints c.
Removing the head relay board
(See Fig.4)
Remove the E washer attaching the load arm using
a pincette or something like that and remove the
spring d.
Move the part of the load arm marked upwards to
release it from the axis of rotation. Then rotate the
load arm in the direction of the arrow to remove it
from the cach.
Removing the load arm (See Fig.5)
Prior to performing the following procedure, remove
the head relay board.
Remove the screw Dattaching the sub chassis.
Push the tab ein the direction of the arrow to detach
the one side of the sub chassis. Then release the
sub chassis from the tab f.
Removing the sub chassis (See Fig.6)
Prior to performing the following procedure, remove
the head relay board, the load arm and the sub
chassis.
Remove the screw Eattaching the reinforce bracket.
Remove the reinforce bracket.
Push the tab gfixing the cassette holder in the
direction of the arrow and open the cassette holder
and the holder arm upward until they stop at an
angle of 45 degrees. Move the two joints hto the
side and remove the cassette holder and the holder
arm from the shaft.
Removing the cassette holder and the
holder arm in the eject mode
(See Fig.7 and 8)
Fig.4 CSoldering b Joint c
Fig.6
Tab f
D
Tab e
Cach
Head relay board
Head relay board
Fig.7
Reinforce bracket
Reinforce
bracket
E
Cassette holder
Sub chassis
Head relay
board
Joint h
Holder arm
Load arm
Joint h
tab g
Fig.5
Spring d
Load arm E washer
Cassette mecha chassis

KS-FX8R
1-8
Prior to performing the following procedure, remove
the head relay board, the load arm, the sub chassis,
the cassette holder, the holder arm and the reel disc
board.
Remove the belt on the bottom of the cassette
mechanism ass’y.
Remove the slit washer attaching the flywheel on the
upper side of the cassette mechanism ass’y and pull
out the flywheel downward. Then remove another
flywheel in the same way.
1.
2.
3.
Removing the flywheel
(See Fig.10 and 12)
Prior to performing the following procedure, remove
the head relay board, the load arm, the sub chassis,
the cassette holder and the holder arm.
Disengage the part ninside of the reel driver which
engages with the shaft, using a pincette or
something like that. Then remove the reel driver from
the shaft.
Remove the reel driver spring and the reel table.
Removing the reel disc ass’y( I )
(See Fig.12 to 14)
When reassembling, make sure to use
a new slit washer.
ATTENTION:
Fig.10
Cassette mechanism ass’y
Tab k
Reel disc board
Soldering j
Tab k
G
G
Motor Belt
Flyhwheel
Fig.12
Plate
The part n
Reel driver
Reel disc ass’y( II )
Push aside
the gear
Tabs o
Reel disc
ass’y( I )
The part n
Reel driver
Tab o
Fig.13
Reel driver
Shaft
The part n
Fig.14
Reel driver spring
Reel table
Slit washer
Slit washer

KS-FX8R
1-9
Release the plate from the three tabs o.
Push aside the gear over the reel table using a
pincette or something like that.
Remove the reel disc ass’y ( II ) as with the reel disc
ass’y ( I ).
1.
2.
3.
Removing the reel disc ass’y( II )
(See Fig.12 to 15)
Do not break the front panel tab fitted
to the metal cover.
ATTENTION:
Prior to performing the following
procedure, remove the reel disc ( I ).
ATTENTION:
Fig.15
Push aside the gear and reattach the reel disc Ass’y( I ).
Reel disc ass’y( II )

KS-FX8R
1-10
Adjustment method
Test Instruments reqired for adjustment
1. Digital osclloscope(100MHz)
2. Frequency Counter meter
3. Electric voltmeter
4. Wow & flutter meter
5. Test Tapes
VT724 ....................... for DOLBY level measurement
VT739 ............ For playback frequency measurement
VT712 ....For wow flutter & tape speed measurement
VT703 ..................... For head azimuth measurement
6. Torque gauge .................... Cassette type for CTG-N
(mechanism adjustment)
Measuring conditions(Amplifier section)
Power supply voltage .............. DC14.4V (10.5 - 16V)
Load impedance ........... 4 (2Speakers connection)
Line out............................................................ 20k
Standard volume position
Balance and Bass,Treble volume .Fader
:Center(Indication"0")
Loudness,Dolby NR,Sound,Cruise:Off
Volume position is about 2V at speaker output with
following conditions.Playback the test tape VT721.
AM mode 999kHz/62dB,INT/400Hz,30%
modulation signal on recieving.
FM mono mode 97.9MHz/66dB,INT/400Hz,22.5kHz
deviation pilot off mono
FM stereo mode 1kHz,67.5kHz dev. pilot7.5kHz dev.
Output level 0dB(1 V,50 /open terminal)

KS-FX8R
1-11
Playback head
Head azimuth screw
Fixed screw
Height adjusting screw c
Height adjusting screw b
Height adjusting screw a
Arrangement of adjusting & test points
Head section view
Cassette mechanism
(Surface)
Tape speed adjust
Motor assembly
Playback head
Azimuth screw

KS-FX8R
1-12
Extension cord
: EXTKSRT002-6P
EXTKSRT002-6P
Front panel assembly
Main board
Cassette mechanism
Information for using a car audio service jig
1. For 1995 and 1996 , we're advancing efforts to make our extension cords common for all car audio products.
Please use this type of extension cord as follows.
2. As a U-shape type top cover is employed, this type of extension cord is needed to check operation of the
mechanism assembly after disassembly.
3. Extension cord : EXTKSRT002-6P ( 6 pin extension cord ) For connection between mechanism assembly
and main board assembly.
Check for mechanism driving section such as motor ,etc..
Disassembly method
1. Remove the bottom cover.
2. Remove the front panel assembly.
3. Remove the top cover .
4. Install the front panel.
5. Confirm that current is being carried by connecting
an extension cord jig.
Note
Available to connect to the CN701 connector when in-
stalling the front panel.

KS-FX8R
1-13
Mechanism adjustment section
Item Adjusting & Confirmation Methods Adjust Std. Value
"Head Height Adjustment"
Note
Adjust the azimuth directly. When you adjust the height us-
ing a mirror tape, remove the cassette housing from the
mechanism chassis.
After installing the cassette housing, perform the azimuth
adjustment.
1.load the mirror tape ( SCC-1659 ). Adjust with height
adjustmentscrew (a) and azimuth adjustment screw (b) so
that line "A" of the mirror tape runs in the center between
Lch and Rch in the reverse play mode.
2.After switching from REV to FWD then to REV, check that
the head position set in procedure "1" is not changed.
*If the position has shifted, adjust again and check.
3.Adjust the azimuth screw (b) so that line "B" of the mirror
tape runs in the center between Lch and Rch in the forward
play mode.
"Head Azimuth Adjustment"
1.Load the test tape ( VT724: 1kHz ) and play it back in the
reverse play mode. set the Rch output level to maximum.
2.Load the test tape ( VT703: 10kHz ) and play it back in the
forward play mode. Adjust the Rch and Lch output levels
tomaximum, with azimuth adjustment screw (b).
In this case, the phase difference should be within 45 .
3.Engage the reverse mode and adjust the output level to
maximum, with azimuth adjustment screw (c).
*The phase difference should be 45_Kor more.
4.When switching between forward and reverse modes, the
difference between channels should be within 3dB.
*Between FWD Lch and Rch, REV Lch and Rch.
5.When the test tape ( VT721 : 315Hz ) is played back, the
level difference between channels should be within 1.5dB.
1.Check to see if the reading of the frequency counter & Wow
flutter meter is within 2940-3090 Hz( FWD/REV ), and less
than 0.35% ( JIS RMS ).
2.In case of out of specification, adjust the motor with a built-
in volume resistor.
1.Play the test tape ( VT724 : 1kHz ) back and set the volume
position at 2V.
2.Play the test tape ( VT739 )back and confirm 0 +3dB at1kHz/
-
8kHz and -4+2dB at 1kHz/125Hz.
3.When 8kHz is out of specification, it will be necessary to
read adjust the azimuth.
Head shield
Head shield
The head is at low position
during FWD.
The head is at height position
during REV.
A Line
B Line
Phase
screw (c) screw (a)
screw (b)
Head azimuth
screw Fixed screw
045
Built-in
volume resistor Tape Speed
2940-3090Hz
Wow&Flutter
Less than
0.35%
(JIS RMS)
Speaker out
1kHz/8kHz
: 0dB_}3dB,
125Hz/1kHz
: -4dB+2dB,
1.Head azimuth
2.Tape Speed and
Wow & Flutter
3.Playback
Frequency
response

KS-FX8R
1-14
Pin No. Port Name I/O Descriptions
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
KEY 0
KEY 1
KEY 2
LEVEL
SM
SQ
LCDCE
LCDDA
LCDSCK
BUSI/O
UNLOCK
BUSSI
BUSSO
BUSSCK
NC
NC
NC
NC
NC
NC
GNDPORT
VDDPORT
AM
AFCK
MONO
FM
SEEK/STP
NC
IFC
VDDPLL
FMOSC
AMOSC
GNDPLL
AMEO
FMEO
IC
SD/ST
STAGE0
NC
F/R
I
I
I
I
I
I
O
O
O
I
-
I
O
I/O
-
-
-
-
-
-
-
-
O
O
O
O
O
I
I
-
I
-
-
O
O
-
I
I
-
O
Key input 0
Key input 1
Key input 2
Level meter input
S.meter level input
S.Quality level input
CE output to LCD driver
Data output to LCD driver
Clock output to LCD driver
I/O selector output for J-BUS, H : OUT, L: INPUT
Non connect
J-BUS Data input
J-BUS Data output
J-BUS Clock in/output
Non connect
Non connect
Non connect
Non connect
Non connect
Non connect
Port GND
Port Vdd
Non connect
AF check output, L: AF check
Monaural on /off selecting output, H:mono on
FM/AM switching output L : FM H : AM
Auto seek /stop selecting output, H: Seek, L:Stop
Pulse signal input port for Cruise control
FM/AM midle frequency counter input
PLL Vdd
FM/AM limited generator frequency input
None connect
PLL GND
AM error out output
FM error out output
GND
Station detector, Stereo signal input, H:Find Station, L:Stereo
Pull up
Non connect
Main motor output
UPD178018AGC-551 (IC701) : Main system control CPU
1. Pin layout
2. Pin function
1
20
60
41
21 ~ 40
80 ~ 61
~ ~
Description of major ICs

KS-FX8R
1-15
Pin No. Port Name I/O Descriptions
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
NC
NC
TELMUTE
TAPEIN
I2CCLK
I2CDAO
I2CDAI
NC
NC
NC
NC
NC
NC
NC
TAPE
TUNER
CD
NC
NC
MUTE
POWER
NC
NC
NC
NC
NC
ON
STOP
RDSCK
RDSDA
REMOCON
DETACH
BUSINT
REGCPU
GND
X2
X1
REGOSC
VDD
RESET
-
-
O
I
O
O
I
-
-
-
-
-
-
-
-
-
-
-
-
O
O
-
-
-
-
-
I
O
I
I
I
I
I
-
-
-
I
-
-
-
Non connect
Non connect
Telephone mute signal detection input
TAPE input
I2C information clock output
I2C information data output
I2C information clock input
Non connect
Non connect
Non connect
Non connect
Non connect
Non connect
Non connect
Non connect
Non connect
Non connect
Non connect
Non connect
Mute output
Power ON /OFF switching output , H : power on
Non connect
Non connect
Non connect
Non connect
Non connect
CPU power supply
STOP signal output terminal
Clock input for RDS
RDS data input
Remocom input
Detach signal input H : Power save
Cut-in input for J-BUS signal
Regulator for CPU power supply, Connect the GND with0.1 F.
Ground
Connecting the crystal oscillator for system clock
Connecting the crystal oscillator for system clock
Regulator for oscillator circuit.Connect the GND with 0.1 F.
Vdd
Pull up

KS-FX8R
1-16
BA4905-V3 (IC901) : Regulator
1.Pin layout
2.Block diagram
12 34 56 78 9101112
EXT
EXT ACC AUDIO 9V CTRL ILM 10V GND
RESET
RESET COMP VDD 5.7V CD 8V VCC AJ
1 2 3 4 5 6 7 8 9 10 11 12
37K
5K
REGULATOR
OIVPC

KS-FX8R
1-17
3.Pin function BA4905-V3
If VDD voltage becomes 4V or less, RESET output becomes low level.
This outout voltage is approximately 0.5V lower than VCC, and max
output current is 300mA.
A voltage supply for ACC block this outout voltage is approximately
0.7V lower than VDD'S. The max output current is 100mA.
Control of the COMP output by inputting voltage.
This output voltage is 5.7V, and max output current is 100mA.
This voltage supply is for microcomputer. Whenever block up voltage
supply is connected. the output keeps on running.
This output voltage is 9.0V, and max output current is 500mA.
This voltage supply for AUDIO.
This output voltage is 8.0V, and max output current is 1A.
This voltage supply for CD.
Output selector of CD, AUDIO,ILM and EXT.
To be connected with the BACK UP of car.
This output voltage is 10V, and max output current is 500mA.
Output voltage is adjustable.
Putting a resistance between ILM and AJ or between AJ and GND
makes ILM output voltage adjustable.
Ground.
1
2
2
4
5
6
7
8
RESET
EXT output
COMP output
ACC
VDD output
AUDIO output
CD output
CTRL
9
10
11
12
VCC
ILM output
AJ
GND
1 2 3 4 5 6 7 8 9 10
GND OUT1 P1 VZ IN1 IN2 VCC1 VCC2 P2 OUT2
Input Output Mode
IN1 IN2 OUT1 OUT2
Brake
0 0 0 0
1 0 1 0
0 1 0 1
1 1 0 0
CLOCKWISE
COUNTER-CLOCKWISE
Brake
LB1641 (IC402) : DC motor driver
1. Pin layout
2. Pin function

KS-FX8R
1-18
2. Pin function
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
PBTC1
PBOUT1
OUTREF1
TAPEIN1
Vcc
NC
LINEOUT1
TCH1
NC
MSLPF
G2FB
G1FB
MSTC
MSOUT
NC
NRSW
MUTESW
TAPESW
DRSW
MSMODE
MSSW
NC
TCH2
LINEOUT2
Pin No. Symbol
-
O
O
I
-
-
O
-
-
-
-
-
-
O
-
I
I
I
I
I
I
-
-
O
Playback equalizer amplifier
capacitance
Playback equalizer amplifier
output
Output reference
TAPE input
Power supply
Line output
Time constant for the HLS
Cut-off frequency adjustment
of the music sensor LPF
Music signal interval detection
Music signal interval detection
Time constant for detecting
music signal interval
Music sensor out
No use
Dolby NR control
Mute function control
Playback equalizer amplifier
control
Head select control
Music sensor mode control
Music sensor control
Time constant for the HLS
Line output
I/O Function
Pin No. Symbol
I/O Function
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
DIREF
GND
TAPEIN2
OUTREF2
PBOUT2
PBTC2
PBFB2
PBRIN2
PBGND
PBFIN2
VCT
PBREF
PBFIN1
PBGND
PBRIN1
PBFB1
-
-
I
O
O
-
I
I
-
I
O
O
I
-
I
I
Resistance for setting the
reference
Ground
TAPE input
Output reference
Playback equalizer amplifier
output
Playback equalizer amplifier
capacitance
Playback equalizer amplifier
feedback
Playback equalizer amplifier
input
Playback equalizer amplifier
ground
Playback equalizer amplifier
input
Center
Playback equalizer amplifier
reference
Playback equalizer amplifier
input
Playback equalizer amplifier
ground
Playback equalizer amplifier
input
Playback equalizer amplifier
feedback
PBFB2
PBRIN2
PBGND
PBFIN2
VCT
PBREF
PBFIN1
PBGND
PBRIN1
PBFB1
MSMODE
DRSW
TAPESW
MUTESW
NRSW
MSOUT
MSTC
G1FB
G2FB
PBTC2
PBOUT2
OUTREF2
TAPEIN2
GND
DIREF
LINEOUT2
TCH2 NC
MSSW
PBTC1
PBOUT1
OUTREF1
TAPEIN1
Vcc
NC
LINEOUT1
TCH1
NC
MSLPF
12345678910
30 29 28 27 26 25 24 23 22 21
20
19
18
17
16
15
14
13
12
11
31
32
33
34
35
36
37
38
39
40
7k/12k
300k
F2
F1
30k
30k
45k
300k
7k/12k
F3
OFF/B
100k
T1
-
+
+
-
70 /120
1
1T2
100k OFF/B
NR
NR
BIAS
MUTE
TAPE EQ
FWD/RVS
LPF +
-DET
Vcc
MS MODE
NR MODE
MS ON/
OFF
-
+
NC
+
-
1.Pin layout & block diagram
CXA2560Q (IC401) : Dolby B type noise reduction system with play back equalizer amp.
70 /120

KS-FX8R
1-19
HA13158A (IC301) : Power amp
1. Pin layout
2. Block diagram
IN1
IN2
IN3
IN4
STBY
2
1
11
13
23
10
TAB
PROTECTOR (ASO
SURGE, TSD)
INPUTBUFFER1
INPUTBUFFER2
INPUTBUFFER3
INPUTBUFFER4
AMP1
AMP2
AMP3
AMP4
MUTE
PVCC1PVCC2
INVCC
+
-
+
-
+
-
+
-
12 22
14 18 6
3
4
5
7
8
9
15
16
17
19
20
21
1 ~ 23

KS-FX8R
1-20
Vcc Vcc
Input
See Function Table
1A
2A
3A
4A
1C
2C
3C
4C
1Y
2Y
2Y
3Y
4Y
Output
Output
Output
Output
Sample as Load Circuit 1
Sample as Load Circuit 1
Sample as Load Circuit 1
1k
1k
S1
CL
Input Outout
C
L
H
H
A
X
L
H
Y
Z
H
L
1
2
3
4
5
6
7
14
13
12
11
10
9
8
HD74HC126FP-X (IC801) : Buffer
1.Pin layout
3.Block diagram
2.Pin function