JVC KS-F171G User manual

SERVICE MANUAL
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LIMITED No.MA007
2003/8
CASSETTE RECEIVER
MA00720038KS-F171G
TABLE OF CONTENTS
1 PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
5 TROUBLE SHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
S.BASS
SEL
DISP
Area Suffix
UN ------------- Asean

1-2 (No.MA007)
SPECIFICATION
Desain dan spesifikasi dapat berubah tanpa pemberitahuan.
BAGIAN AMPLIFIER
AUDIO Output power maksimum Depan 45 watt per chanel
Belakang 45 watt per chanel
Output Power kontinyu
(RMS) Depan 17 watt per chanel dalam 4 Ω, 40 Hz hingga 20 000 Hz dengan tidak lebih dari 0.8% distorsi
harmonis total.
Belakang 17 watt per chanel dalam 4 Ω, 40 Hz hingga 20
000 Hz dengan tidak lebih dari 0.8% distorsi
harmonis total.
Impedansi beban 4 Ω(toleransi antara 4 Ωhingga 8 Ω)
Batas tone kontrol Bass ±10 dB pada 100 Hz
Treble ±10 dB pada 10 kHz
Respon Frekuensi 40 Hz hinga 20 000 Hz
Rasio Sinyal ke suara 70 dB
Level Line-Out/ impedansi 1.0V/beban 20 kΩ(250 nWb/m)
Bagian Radio Batas Frekuensi FM 87.5 MHz hingga 108.0 MHz
AM 531 kHz hingga 1 602 kHz
[Radio FM] Sensitivitas yang dapat digunakan 11.3 dBf (1.0 µV/75 Ω)
50 dB Sensitivitas Ketenangan 16.3 dBf (1.8 µV/75 Ω)
Selektivitas Chanel Alternatif
(400 kHz) 65 dB
Respon Frekuensi 40 Hz hingga 15 000 Hz
Pemisah Stereo 35 dB
Rasio penangkapan 2.0 dB
[Radio AM] Sensitivitas 20 µV
Selektivitas 35 dB
Bagian Dek Kaset Bagian Dek Kaset 0.15% (WRMS)
Waktu Menggulung cepat 190 detik (C-60)
Respon Frekuensi 50 Hz hingga 14 000 Hz (tape normal)
Rasio Sinyal ke suara 52 dB
Pemisah Stereo 40 dB
UMUM Power yang diperlukan Tegangan Operasional DC 14.4 V
(diperbolehkan antara 11V hingga 16 V)
Sistem Grounding Ground Negatif
Temperatur kerja yang diperbolehkan 0ºC hingga +40ºC
Dimensi (L ×T ×K) Ukuran pemasangan 182 mm ×52 mm ×150 mm
Ukuran panel 188 mm ×58 mm ×11 mm
Berat 1.3 kg (tidak termasuk aksesoris)

(No.MA007)1-3
SECTION 1
PRECAUTION
1.1 Safety Precautions
!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.

1-4 (No.MA007)
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

(No.MA007)1-5
SECTION 3
DISASSEMBLY
3.1 Main body
3.1.1 Removing the front panel assembly
(See Fig.1)
(1) Press the release button and remove the front panel as-
sembly.
Fig.1
3.1.2 Removing the bottom cover
(See Fig.2)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Turn the body upside down.
(2) Insert a screwdriver under the joints to release the two
joints aon the left side, the two joints bon the right side and
the joint con the back of the body, then remove the bottom
cover from the body.
CAUTION:
When releasing the joint cusing a screwdriver, do not damage
the board.
Fig.2
3.1.3 Removing the front chassis
(See Fig.3)
• Prior to performing the following procedure, remove the front
panel assembly and bottom cover.
(1) Remove the screw Aon each side of the body.
(2) Release the two joints dand the two joints eon the sides,
then remove the front chassis toward the front.
Fig.3
Front panel assembly
Release button
Bottom cover
Joint b
Joint b
Joint c
Joint a
Joint a
Joint d
Front chassis
A
Joint e
Joint dJoint e

1-6 (No.MA007)
3.1.4 Removing the heat sink
(See Fig.4)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Remove the screw Band two screws Cattaching the heat
sink on the left side of the body, and remove the heat sink.
Fig.4
3.1.5 Removing the rear panel
(See Fig.5 )
• Prior to performing the following procedure, remove the front
panel assembly and bottom cover.
(1) Remove the two screws D, one screw Eand three screws
Fattaching the rear panel on the back of the body.
Fig.5
3.1.6 Removing the main board
(See Fig.6)
• Prior to performing the following procedure, remove the front
panel assembly, bottom cover, front chassis, heat sink and
rear panel.
(1) Remove the two screws Gattaching the main board on the
top chassis.
(2) Disconnect the two connectors CN901 and CN721 on the
main board from the cassette mechanism assembly.
Fig.6
Heat sink
C
B
C
D
FF
E
D
GG
Main board
CN901
CN721

(No.MA007)1-7
3.1.7 Removing the cassette mechanism assembly
(See Fig.7)
• Prior to performing the following procedure, remove the front
panel assembly, bottom cover, front chassis, heat sink, rear
panel and main board.
(1) Remove the four screws Hattaching the cassette mecha-
nism assembly from the top chassis.
Fig.7
3.1.8 Removing the head amplifier board
(See Fig.8)
• Prior to performing the following procedure, remove the front
panel assembly, bottom cover, front chassis, heat sink, rear
panel, main board and cassette mechanism assembly.
(1) Disconnect the wire from CJ901 on the head amplifier
board.
(2) Remove the one screw Jattaching the head amplifier
board.
(3) Move the head amplifier board in the direction of the arrow
to release the two joints f, the head amplifier board can be
removed.
Fig.8
3.1.9 Removing the relay board
(See Fig.9)
• Prior to performing the following procedure, remove the front
panel assembly, bottom cover, front chassis, heat sink, rear
panel, main board and cassette mechanism assembly.
(1) Disconnect the wire from CP722 on the relay board.
(2) Remove the one screw Kattaching the relay board.
(3) Move the relay board in the direction of the arrow to release
the joint g, the relay board can be removed.
Fig.9
HH
HH
Top chassis
Cassette mechanism assembly
J
CJ901
Head amplifier board
Joint f
Joint f
To head relay board
K
CP722
Relay board
Joint g

1-8 (No.MA007)
3.1.10 Removing the mecha bracket
(See Fig.10)
• Prior to performing the following procedure, remove the front
panel assembly, bottom cover, front chassis, heat sink, rear
panel, main board, cassette mechanism assembly, head am-
plifier board and relay board.
(1) Remove the four screws Lattaching the mecha bracket.
Fig.10
3.1.11 Removing the switch (LCD & key) board
(See Fig.11~13)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Remove the four screws Mattaching the rear cover on the
back of the front panel assembly.
(2) Release the eleven joints h, the front panel and the rear
cover become separate.
(3) Remove the switch board from the rear cover.
Fig.11
Fig.12
Fig.13
Mecha bracket
L
L
L
L
M
M M
M
Joint h
Joint h
Joint h
Joint h
Switch (LCD & Key) board

(No.MA007)1-9
3.2 Cassette mechanism assembly
• Prior to performing the following procedures, remove the head
amplifier board, the relay board and the mechanism bracket.
3.2.1 Removing the direction switch board
(See Fig.1)
(1) Unsolder the three wires aon the direction switch board.
(2) Remove the one screw Aattaching the direction switch
board.
3.2.2 Removing the FF / REW lever assembly
(See Fig.1)
(1) Remove the screw Battaching the FF / REW lever assem-
bly on the back of the cassette mechanism assembly.
(2) Remove the screw Con the upper side of the FF / REW
lever assembly.
(3) Lift and pull forward the FF / REW lever assembly to disen-
gage the joints b, c, dand e.
3.2.3 Reattaching the FF / REW lever assembly
(See Fig.1)
(1) Reattach the FF / REW lever assembly to the joint con the
back of the chassis.
(2) Reattach the pinch-roller shaft e, the change lever dand
the return link eto the chassis.
Fig.1
3.2.4 Removing the playback head
(See Fig.2)
• Prior to performing the following procedure, remove the direc-
tion switch board and the FF / REW lever assembly.
(1) Remove the screw Dattaching the playback head.
(2) Remove the Cwasher and pull out the FF roller.
(3) Remove the Ssupport plate, the A arm spring (a) and (b),
the playback head.
ATTENTION:
The A arm spring (a) differs from the A arm spring (b).
3.2.5 Removing the pinch-roller (R) and (F) assembly
(See Fig.2)
• Prior to performing the following procedure, remove the direc-
tion switch board and the FF / REW lever assembly.
(1) Remove the P arm spring (f) in the pinch-roller (F) assem-
bly from the chassis.
(2) Remove the P arm spring (r) in the pinch-roller (R) assem-
bly from the chassis.
(3) Draw out the pinch roller (F) and (R) assembly from the
shaft.
ATTENTION:
The P arm spring (f) differs from the P arm spring (r).
ATTENTION:
The pinch roller (F) assembly differs from the pinch roller (R)
assembly.
Fig.2
C
FF / REW lever assembly
Joint c
Joint b
B
A
Direction switch board
Joint d
Joint e
Soldering a
A arm spring (b) A arm spring (a)
Pinch-roller (R) assembly Pinch-roller (F) assembly
Shaft Shaft
S support plate
D
C washer
P arm spring (f)
P arm spring (r)
Remove the P arm spring (f)
from the chassis.
Remove the P arm spring (r)
from the chassis.
Playback head
FF roller

1-10 (No.MA007)
3.2.6 Removing the cassette hanger / cassette holder
(See Fig.3)
• Prior to performing the following procedure, remove the FF /
REW lever assembly.
(1) From the rear of the unit, bend the two tabs foutwards and
disengage the two joints gin the direction of the arrow.
(2) Push the eject lever and remove the cassette holder from
the playback head. Disengage the two joints hof the cas-
sette hanger / cassette holder and the eject lever in the di-
rection of the arrow.
(3) Lift the cassette hanger / cassette holder and disengage
the joint i of the return link and the eject lever.
Fig.3
3.2.7 Removing the reel disc assembly
(See Fig.4)
• Prior to performing the following procedure, remove the FF /
REW lever assembly and the cassette hanger / cassette hold-
er.
(1) Remove the C washer and pull out reel disc assembly.
ATTENTION:
Replace with a new C washer when reattaching.
Fig.4
3.2.8 Removing the motor assembly
(See Fig.5)
(1) Unsolder the two wires jon the motor assembly.
(2) Turn over the cassette mechanism assembly and remove
the main belt and the sub-belt from the motor pulley.
ATTENTION:
The main belt can now be removed.
(3) Remove the two screws Gattaching the motor assembly.
Fig.5
Cassette holder
Cassette hanger
Return link
Joint i
Eject lever
Joint h
Joint h
Joint g
Joint g Tab f
Tab f
Chassis
Reel disc assembly
C washer
C washer
Flywheel (BF)
Flywheel (BR)
E
E
E
F
G
G
Main-belt
Reel base assembly
Sub-belt
Motor assembly
Motor pulley
Soldering j

(No.MA007)1-11
3.2.9 Removing the Flywheel (BF) and (BR) assembly
(See Fig.4 and 5)
• Prior to performing the following procedure, remove the cas-
sette hanger / cassette holder.
(1) From the upper side of the cassette mechanism assembly,
remove the C washer from each shaft of the flywheel (BF)
and (BR).
(2) Turn over the cassette mechanism assembly and remove
the main belt. Pull out the flywheel (BF) and (BR) down-
ward respectively.
Fig.4
Fig.5
3.2.10 Removing the reel base assembly
(See Fig.5 and 6)
(1) Raise the part kof the reel base assembly slightly and re-
move the selector link (B) on the front side of the cassette
mechanism assembly by turning it as shown in Fig.6.
(2) Remove the three screws Eand the one screw Fon the
underside of the cassette mechanism assembly.
ATTENTION:
The reel base assembly is not repairable. Handle with care.
Fig.6
Fig.7
Reel disc assembly
C washer
C washer
Flywheel (BF)
Flywheel (BR)
E
E
E
F
G
G
Main-belt
Reel base assembly
Sub-belt
Motor assembly
Motor pulley
Soldering j
Selector link (B).
Pinch-roller (R) assembly
Turn the selector link (B).
k
Inside of the reel base assembly

1-12 (No.MA007)
3.2.11 Removing the mute switch board (See Fig.8)
(1) Unsolder the two wires lon the mute switch board on the
back of the cassette mechanism assembly.
(2) Remove the screw Hattaching the mute switch board.
Fig.8
3.2.12 Removing the power switch
(See Fig.9)
• Prior to performing the following procedure, remove the motor
assembly.
(1) Unsolder the two wires mon the power switch on the side
of the cassette mechanism assembly.
(2) Remove the screw Iattaching the power switch.
Fig.9
Cassette mechanism assembly
Soldering l
HMute switch board
Rower switch
Motor assembly
Soldering m
IPower switch
Cassette mechanism assembly

(No.MA007)1-13
SECTION 4
ADJUSTMENT
4.1 Adjustment method
Test instruments required for adjustment
(1) Digital oscilloscope (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
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.
Measuring conditions (Amplifier section)
• Power supply voltage.............. DC14.4V (11V to 16V allowance)
• Load impedance............ 4Ω(4Ωto 8Ωallowance)
• Line out level/Impedance..............1.0V/20k load (250 nWb/m)
AM mode 999kHz/62dB, INT/400Hz, 30%
modulation signal on receiving.
FM mono mode 97.9MHz/66dB, INT/400Hz, 22.5kHz
deviation pilot off mono
FM stereo mode 1kHz, 67.5kHz dev. pilot 7.5kHz dev.
Output level 0dB (1µV,50Ω/open terminal)

1-14 (No.MA007)
Information for using a car audio service jig
(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 : EXTKSRT002-6P ( 6 pin extension cord ) For connection between mechanism assemblyand main board.
(4) Check for mechanism driving section such as motor ,etc.
Disassembly method
(1) Remove the front panel assembly.
(2) Remove the bottom cover.
(3) Remove the front chassis.
(4) Remove the heat sink.
(5) Remove the rear panel
(6) Remove the main board.
(7) Reattach the heat sink with the two screws D. (Refer to DISASSEMBLY.)
(8) Reattach the rear panel with the screw G. (Refer to DISASSEMBLY.)
(9) Reattach the front chassis assembly with the screw B. (Refer to DISASSEMBLY.).
(10) Reattach the front panel assembly.
(11) Confirm that current is being carried by connecting an extension cord jig.
NOTE:
Available to connect to the CJ701 connector when installing the front panel.
CAUTION :
Be sure to attach the heat sink and rear panel on the power amplifier IC and regulator IC of a main board when supplying
the power.If voltage is applied without attaching those parts, the power amplifier IC and regulator IC will be destroyed
by heat.
EXTKSRT002-6P
Extension cord
: EXTKSRT002-6P
Main board
Cassette mechanism
Front Panel assembly

(No.MA007)1-15
Arrangement of adjusting & test points
Playback head
Head azimuth screw
Fixed screw
Height adjusting screw c
Height adjusting screw b
Height adjusting screw a
Head section view
Cassette mechanism
(Surface)
Tape speed adjust
Motor assembly
Playback head
Azimuth screw

1-16 (No.MA007)
The tuner section is of an adjustment-freedesign. In case the tuner is in trouble, replace the tuner pack.
Item Conditions Adjustment and Confirmation methods S.Values Adjust
1. Head azi-
muth adjust-
ment
Test tape:
SCC-1659
VT703 (10kHz)
Head height adjustment
Adjust the azimuth directly. When you adjust the height
using a mirror tape, remove the cassette housing from
the mechanism chassis. After installing the cassette
housing, perform the azimuth adjustment.
(1) Load the SCC-1659 mirror tape. Adjust with height
adjustment screw 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 with azimuth adjustment screw B so that line
B of the mirror tape runs in the center between Lch
and Rch in the forward play mode.
Test tape:
VT724 (1kHz)
VT703 (10kHz)
VT721 (315Hz)
Head azimuth adjustment
(1) Load VT724 (1kHz) and play it back in the reverse
play mode. Set the Rch output level to max.
(2) Load VT703 (10kHz) and play it back in the forward
play mode. Adjust the Rch and Lch output levels to
max, with azimuth adjustment screw B. In this case,
the phase difference should be within 45 .
(3) Engage the reverse mode and adjust the output lev-
el to max, with azimuth adjustment screw C.(The
phase difference should be 45 or more.)
(4) When switching between forward and reverse
modes, the difference between channels should be
within 3dB. (Between FWD L and R, REV L and R.)
(5) When VT721 (315Hz) is played back, the level differ-
ence between channels should be within 1.5dB.
2. Tape speed
and wow flut-
ter confirma-
tion
Test tape:
VT712 (3kHz) (1) Check to see if the reading of the F, counter / wow flutter meter is within 3015Hz to 3045Hz (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.
Tape speed:
3015Hz to 3045Hz
Wow flutter:
less than 0.35%
Built-in volume
resistor
3. Play back
frequency re-
sponse confir-
mation
Test tape:
VT724 (1kHz)
VT739 (63Hz /
1kHz / 10kHz)
(1) Play test tape VT724, and set the volume position at
2V.
(2) Play test tape VT739 and confirm.1kHz / 10kHz: -1
±3dB,1kHz / 63Hz: 0 ±3dB,
(3) When 10kHz is out of specification, it will be neces-
sary to read adjust the azimuth.
Speaker out
1kHz / 63Hz: 0 ±3dB
1kHz / 10kHz: -1 ±3dB
A line
B line
Head shield
PBHead
FWD Adj B
REV Adj C HEIGHT Adj A
phase
(0 ) (45 )
Head shield
The head is at low position
during.
The head is at High position
during REV.
Output
level:
Maximum

(No.MA007)1-17
SECTION 5
TROUBLE SHOOTING
This service manual does not describe TROUBLE SHOOTING.

(No.MA007)
AV & MULTIMEDIA COMPANY MOBILE ENTERTAINMENT CATEGORY 10-1,1chome,Ohwatari-machi,Maebashi-city,371-8543,Japan
VICTOR COMPANY OF JAPAN, LIMITED
WPC
Printed in Japan

SCHEMATIC DIAGRAMS
RADIO KASET
No.MA007SCH
2003/9
COPYRIGHT 2003 VICTOR COMPANY OF JAPAN, LTD.
KS-F171G
Area Suffix
UN ----------------------------Asean
Contents
Block diagram
Standard schematic diagrams
Printed circuit boards
2-1
2-2
2-5,6
CD-ROM No.SML200309
S.BASS
SEL
DISP

2-4
!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