JVC KS-F171 User manual

SERVICE MANUAL
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LTD. No.49774
2003/01
KS-F171
CASSETTE RECEIVER
49774200301
KS-F171
TABLE OF CONTENTS
1 Important Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
2 Disassembly method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
3 Adjustment method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
4 Description of major ICs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
Area Suffix
U ------- Other Areas
S. BA SS
SEL
D ISP

KS-F171
1-2 (No.49774)
SECTION 1
Important Safety Precautions
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.

KS-F171
(No.49774)1-3
SECTION 2
Disassembly method
2.1 Main body
2.1.1 Removing the front panel assembly
(See Fig.1)
(1) Press the release button and remove the front panel as-
sembly.
Fig.1
2.1.2 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 c using a screwdriver, do not
damage the board.
Fig.2
2.1.3 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 d Joint e

KS-F171
1-4 (No.49774)
2.1.4 Removing the heat sink
(See Fig.4)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Remove the two screws Band two screws Cattaching the
heat sink on the left side of the body, and remove the heat
sink.
Fig.4
2.1.5 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
2.1.6 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
CB C
D
FF
E
D
GG
Main board
CN901
CN721

KS-F171
(No.49774)1-5
2.1.7 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
2.1.8 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
HH
HH
Top chassis
Cassette mechanism assembly
joint f
J
CJ901
Head amplifier board
To head relay board
joint f

KS-F171
1-6 (No.49774)
2.1.9 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
2.1.10 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
joint g
K
CP722
Relay board
Mecha bracket
L
L
L
L

KS-F171
(No.49774)1-7
2.1.11 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
M
M M
M
Joint h
Joint h
Joint h
Joint h
Switch (LCD & Key) board

KS-F171
1-8 (No.49774)
2.2 Cassette mechanism assembly
• Prior to performing the following procedures, remove the head
amplifier board, the relay board and the mechanism bracket.
2.2.1 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.
2.2.2 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.
2.2.3 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
2.2.4 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).
2.2.5 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

KS-F171
(No.49774)1-9
2.2.6 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
2.2.7 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
2.2.8 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

KS-F171
1-10 (No.49774)
2.2.9 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
2.2.10 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