JVC KSFX-893 Service manual
SERVICE MANUAL
CASSETTE RECEIVER
KS-FX893
KS-FX893
KS-FX893
Contents
Safety precaution
Disassembly method
1-2
1-3
COPYRIGHT 2002 VICTOR COMPANY OF JAPAN, LTD.
Adjustment method
Description of major ICs
Area Suffix
UF China
1-11
1-15~24
No.49763
Nov. 2002
1-1
KS-FX893
Safety precaution
!
!
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.
Please use enough caution not to see the beam directly or touch it in case of an
adjustment or operation check.
1-2
KS-FX893
Disassembly method
Removing the front chassis
1.2.Remove the two screws A attaching the front
chassis.
Insert a screwdriver to the two joints a on the side
of the front chassis, two joints b on the right side
and one joint c from upside, then detach the front
chassis toward the front side.
(See Fig.1~2)
A
c
Fig.1
a
b
Removing the heat sink
1. Remove the three screws B attaching the heat sink
on the left side of the body, and remove the heat
sink.
(See Fig.3)
B
a
Front chassis
B
b
Fig.2
B
Heat sink
Fig. 3
1-3
KS-FX893
Removing the bottom cover
1.2.Turn the body upside down.
Insert a screwdriver to the two joints d and two
joints e on both sides of the body and the joint f on
the back of the body, then detach the bottom cover
from the body.
Removing the rear panel
1.
Remoe the front chassis.
2.
Remove the heat sink.
3.
Remove the bottom cover.
(See Fig.4)
(See Fig.5 )
B
d
Bottom cover
e
f
Fig. 4
C
B
B
4.
Remove the seven screws B attaching the rear
panel and one screw C attaching the pine jack on
the back of the body.
Removing the main amplifier board
assembly
1.
Remove the front chassis.
2.
Remove the bottom cover.
3.
Remove the rear panel.
4.
Remove the two screws D attaching the main
amplifier board assembly on the top cover.
5.
Disconnect connector CP701 on the main amplifier
board assembly from the cassette mechanism
assembly.
(See Fig.6)
D
Fig. 5
Main board assembly
D
CP701
Fig. 6
1-4
KS-FX893
Removing the Cassette mechanism
assembly
1.
Remove the front chassis.
2.
Remove the bottom cover.
3.
Remove the main amplifier board assembly.
4.
Remove the fore screws F attaching the cassette
mechanism assembly from the top cover.
(See Fig.7)
Removing the control switch board
(See Fig.8 and 9 )
Cassette mechanism assembly
F
F
Fig. 7
G
F
Top cover
F
G
1.
Remove the front panel unit from the main body.
2.
Remove the four screws G attaching the rear cover
on the back of the front panel unit.
3.
Remove the control switch board from the front
panel unit.
G
LCD & Key control board
Fig. 8
Fig. 9
G
1-5
KS-FX893
y
<Removal of the cassette mechanism>
Cassette mechanism ass’y
Removing the head amplifier board.
(See Fig.1 and 2)
1.
For the 6pin wire extending from connector CN402
on the head amplifier board, disconnect it from the
head relay board.
2.
Disconnect the card wire from connector CN403 on
the head amplifier board.
3.
Remove the screw A attaching the head amplifier
board.
4.
Move the tab a as shown in Fig.2 and remove the
head amplifier board while moving it in the direction
of the arrow.
Removing the cassette mechanism
assembly (See Fig.1 to 3)
1.
Disconnect the 6pin wire from connector CN402 and
the card wire from CN403 on the head amplifier
board (Refer to Fig.1 and 2).
Head relay
board
6pin
wire
CN402
A
CN403
CN402
Fig.1
CN403
Head amplifier board
Fig.2
Head amplifier board
Tab a
2.
Remove the four screws B on the bottom of the
cassette mechanism.
Head amplifier board
B
Cassette mechanism ass’
B
Fig.3
1-6
KS-FX893
Removing the head relay board
(See Fig.4)
1.
Unsolder the soldering b on the head relay board.
2.
Remove the screw C attaching the head relay board.
3.
Remove the head relay board in the direction of the
arrow while releasing the two joints c.
Removing the load arm (See Fig.5)
1.
Remove the E washer attaching the load arm using
a pincette or something like that and remove the
spring d.
2.
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.
Fig.4
Cach
Load arm
Fig.5
Head relay board
Soldering b
C
E washer
Joint c
Spring d
Removing the sub chassis (See Fig.6)
Prior to performing the following procedure, remove
the head relay board.
1.
Remove the screw D attaching the sub chassis.
2.
Push the tab e in 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 cassette holder and the
holder arm in the eject mode
(See Fig.7 and 8)
Prior to performing the following procedure, remove
the head relay board, the load arm and the sub
chassis.
1.
Remove the screw E attaching the reinforce bracket.
2.
Remove the reinforce bracket.
Tab f
Sub chassis
Head relay
board
D
Cassette mecha chassis
Cassette holder
Fig.6
Head relay board
Tab e
Reinforce bracket
E
Reinforce
bracket
tab g
3.
Push the tab g fixing 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 h to the
side and remove the cassette holder and the holder
arm from the shaft.
Joint h
Load arm
Holder arm
Fig.7
Joint h
1-7
KS-FX893
Removing the play head (See Fig.9)
Prior to performing the following procedure, remove
the head relay board and the sub chassis.
1.
Remove the two screws F attaching the play head
(The spring under the play head comes off at the
same time).
Shaft
Joint h
Pinch roller ass’y
Fig.8
Play head
Cassette holder
and holder arm
Joint h
Shaft
Pinch roller ass’y
Removing the pinch roller ass’y
(See Fig.9)
Prior to performing the following procedure, remove
the head relay board and the sub chassis.
1.
Push each tab i in the direction of the arrow and pull
out the pinch rollers on both sides.
Removing the reel disc board
(See Fig.10)
1.
Unsolder the soldering j on the reel disc board.
2.
Push the seven tabs k on the bottom of the cassette
mechanism assembly in the direction of the arrow.
Removing the motor and the sub motor
(See Fig.10 and 11)
Tab i
Tab i
Soldering j
G
Motor
F
Pinch roller ass’y
Fig.9
Reel disc board
Tabs k
Tabs k
G
Tab i
Spring
Tab i
Cassette mechanism ass’y
Flyhwheel
Belt
Fig.10
1.
Unsolder the two soldering l of the motor and the sub
motor.
2.
Release the sub motor from the three tabs m. Push
the sub motor upward and pull out it.
3.
Remove the belt on the bottom of the cassette
mechanism assembly and remove the two screws G
attaching the motor.
ATTENTION:
The motors can be detached before
removing the load arm.
1-8
Sub motor
Tab m
Load arm
Soldering j
Tab m
Soldering l
Tab m
Soldering l
Motor
Fig.11
KS-FX893
Removing the flywheel
(See Fig.10 and 12)
1.
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.
2.
Remove the belt on the bottom of the cassette
mechanism ass’y.
3.
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.
ATTENTION:
When reassembling, make sure to use
a new slit washer.
Removing the reel disc ass’y( )
(See Fig.12 to 14)
Soldering j
G
Motor
Plate
Reel disc board
G
Slit washer
Tab k
Tab o
Cassette mechanism ass’y
Tab k
Belt
Fig.10
Reel driver
The part n
Tabs o
Flyhwheel
Reel disc
ass’y( )
Push aside
the gear
Prior to performing the following procedure, remove
the head relay board, the load arm, the sub chassis,
the cassette holder and the holder arm.
1.
Disengage the part n inside of the reel driver which
engages with the shaft, using a pincette or
something like that. Then remove the reel driver from
the shaft.
2.
Remove the reel driver spring and the reel table.
The part n
Slit washer
Shaft
Fig.13
The part n
Reel driver
Fig.12
Reel driver
Reel driver spring
Reel disc ass’y( )
Reel table
Fig.14
1-9
KS-FX893
Removing the reel disc ass’y( )
(See Fig.12 to 15)
ATTENTION:
1.
Release the plate from the three tabs o.
2.
Push aside the gear over the reel table using a
pincette or something like that.
3.
Remove the reel disc ass’y ( ) as with the reel disc
ass’y ( ).
ATTENTION:
Prior to performing the following
procedure, remove the reel disc ( ).
Do not break the front panel tab fitted
to the metal cover.
Push aside the gear and reattach the reel disc Ass’y( ).
Reel disc ass’y( )
Fig.15
1-10
Adjustment method
KS-FX893
Test instruments required for adjustment
1. Digital oscilloscope(100MHz)
2. Frequency Counter meter
3. Electric voltmeter
4. Wow & flutter meter
5. Test Tapes
MC-109C
VT724
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
...................
.......................
For TAPA CURL confirmation
(without Padd type)
For DOLBY level measurement
(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 1000kHz/62dB,INT/400Hz,30%
modulation signal on receiving.
FM mono mode 97.5MHz/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)
1-11
KS-FX893
Arrangement of adjusting & test points
Cassette mechanism
(Surface)
Motor assembly
Tape speed adjust
Head section view
Azimuth screw A
(Forward)
Playback head
Azimuth screw B
(Reverse)
1-12
Azimuth screw B
(Reverse)
Azimuth screw A
(Forward)
Playback Head
KS-FX893
y
Information f
1. 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 : EXTKSRT002-18P ( 18 pin extension cord ) For connection between mechanism assembly
and main board assembly.
Check for mechanism driving section such as motor ,etc..
or using a car audio service jig
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 CP701 connector when in-
stalling the front panel.
Cassette mechanism
to Cassette mechanism
Extension cord
EXTKSRT002-18P
Main board
to Main board
CP701
Front panel assembl
EXTKSRT002-18P
1-13
KS-FX893
Mechanism adjustment section
Item Adjusting & Confirmation Methods Adjust Std. Value
1. Tape running
adjustment
2. Azimuth
adjustment
confirmation
a) At Forward playmode, using mirror tape, make adjustment
with Azimuth screw A and Azimuth screw B, without curl of 4
parts of head tape guide.
b) At Reverse play mode, using mirror tape, make adjustment
with Azimuth screw A and Azimuth screw B, without tape
curl of 4 parts of head guide.
c) At Forward / Reverse play mode, make confirmation of no
tape curl of 4 parts of head tape guide.
a) At forward play mode, make adjustment of peak of Lch / Rch
output with Azimuth screw A.
* For Oscilloscope litharge corrugation, set 45 as standard.
b) At Reverse play mode, make adjustment of peak of Lch / Rch
output with Azimuth screw B.
* For Oscilloscope litharge corrugation, set 45 as standard.
c) With AC volt meter confirm the difference of output for 4ch
between Lch / Rch at forward play mode and Lch / Rch
Reverse play mode being within 3.0dB.
d) After operation, make confirmation of Lch / Rch azimuth
output being within 1.0dB from adjustment value.
Azimuth
screw A
Azimuth
screw B
2.Tape Speed and
Wow & Flutter
HEAD
Tape guide
OK
HEAD TAPE
1.Check to see if the reading of the frequency counter & W ow
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 builtin volume resistor .
Tape curl NG
0
Phase
Built-in
volume resistor
45
Tape Speed
2940-3090Hz
Wow&Flutter
Less than
0.35%
(JIS RMS)
3.Playback
Frequency
response
1-14
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/
10kHz and -4+2dB at 1kHz/63Hz.
3.When 10kHz is out of specification, it will be necessary to
read adjust the azimuth.
Speaker out
1kHz/10kHz
: 0dB 3dB,
63Hz/1kHz
: -4dB+2dB,
Description of major ICs
TEA6320T-X (IC161) : E. volume
1. Pin layout
2. Block diagram
10 8 9 7 6
KS-FX893
5
12
SDA
1
GND
2
OUTLR
OUTLF
MUTE
TL
B2L
B1L
IVL
ILL
QSL
IDL
ICL
IMD
IBL
IAL
3
4
5
6
7
8
9
10
11
12
13
14
15
16
3. Pin functions
Pin
Symbol
No.
SDA
1
SCL
32
VCC
31
OUTRR
30
OUTRF
29
TR
28
B2R
27
B1R
26
IVR
25
ILR
24
QSR
23
IDR
22
Vref
21
ICR
CD-CH
TAPE
TUNER
20
19
18
17
CAP
IBR
IAR
I/O
Serial data input/output.
I/O
MUTE
21
31
2
19
16
15
13
11
14
22
20
18
17
Functions Functions
POWER
SUPPLY
SOURCE
SELECTOR
23 25 24 26 27 28
VOLUM E 1
+20 to -31 dB
LOUDNESS
LEFT
VOLUM E 1
+20 to -31 dB
LOUDNESS
RIGHT
Pin
No.
17
Symbol
IAR
BASS
LEFT
+15 dB
LOGIC
BASS
RIGHT
+15 dB
I/O
I
Input A right source.
TREBLE
LEFT
+12 dB
TREBLE
RIGHT
+12 dB
FUNCTION
ZERO CROSS
DETECTOR
VOLUM E 2
0 to 55 dB
BALANCE
FENDER REAR
VOLUM E 2
0 to 55 dB
BALANCE
FENDER FRONT
HC BUS
REC
VOLUM E 2
0 to -55dB
BALANCE
FENDER FRONT
VOLUM E 2
0 to -55dB
BALANCE
FENDER REAR
3
4
32
1
29
30
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
GND
OUTLR
OUTLF
TL
B2L
B1L
IVL
ILL
QSL
IDL
MUTE
ICL
IMO
IBL
IAL
Ground.
-
output left rear.
O
output left front.
O
Treble control capacitor left channel or
I
input from an external equalizer.
Bass control capacitor left channel or
output to an external equalizer.
Bass control capacitor left channel.
-
Input volume 1. left control part.
I
Input loudness. left control part.
I
Output source selector. left channel.
O
Not used
-
Not used
-
Input C left source.
I
Not used
-
Input B left source.
I
Input A left source.
I
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
IBR
CAP
ICR
Vref
IDR
QSR
ILR
IVR
B1R
B2R
TR
OUTRF
OUTRR
Vcc
SCL
I
Input B right source.
-
Electronic filtering for supply.
I
Input C right source.
-
Reference voltage (0.5Vcc)
-
Not used
O
Output source selector right channel.
I
Input loudness right channel.
I
Input volume 1. right control part.
-
Bass control capacitor right channel
Bass control capacitor right channel or
O
output to an external equalizer.
Treble control capacitor right channel or
I
input from an external equalizer.
O
Output right front.
O
Output right rear.
-
Supply voltage.
I
Serial clock input.
1-15
KS-FX893
LC72366-9987 (IC701) : System CPU
1. Pin layout
24 ~ 1
25
80
~
40
41 ~ 64
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
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
J-BUS SCK
TEL-MUTE
DIMMER IN
EVOL SCK
POWER ANT
DEMEROUT
FF/REW MODE
SEEK/STOP
RADIO/TAPE
BEEP LEVEL
Symbol FunctionPin No.
XIN
GND
J-BUS SI
J-BUS SO
J-BUS I/O
LCD SO
LCD SCK
LCD CE
EVOL SO
OPEN
MUTE
CD ILLUM
NC
NC
NC
NC
NC
NC
KS1
KS0
K3
K2
K1
K0
Vdd
TEST
MONO
PWR-CNT
ACC
KICK
65
~
I/O
I
Crystal oscillator input port
-
Connect to GND
I
Data input for J-BUS information
O
Data output for J-BUS information
O
Clock output for J-BUS information
O
Switching signal output for J-BUS information I/O, H:Out L:In
I
Telephone mute signal input
O
Data output for LCD driver
O
Information clock output for LCD driver data
O
Chip enable output for LCD driver
-
None connection
O
Data output for electrical volume
O
Clock output for electrical volume information
I
Door open detect input
I
Power ant ON signal input
I
Mute signal input
-
Non connection
O
DIMMER control signal output
-
Non connection
-
Non connection
-
Non connection
-
Non connection
-
Non connection
-
Non connection
-
Non connection
O
Diode matrix output port for initial establishing
I
Diode matrix output port for initial establishing
I
Diode matrix output port for initial establishing
-
Non connection
I
Diode matrix output port for initial establishing
-
5V power supply port (+B)
I
Turn on all light indicator of LCD, L: All light a LED indicator
O
FF/REW mode select signal output
O
H:Auto seek, L: Stop Use both as IF count REQ and Seek/Stop
O
Forced monaural output port, H:Turn on Forced monaural
-
Non connection
-
Non connection
O
"H" : Turn on power
-
Non connection
-
Non connection
1-16
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