JVC KD-SHX751 User manual

SERVICE MANUAL
COPYRIGHT © 2005 Victor Company of Japan, Limited No.MA163
2005/4
CD/SD RECEIVER
MA16320054
KD-SHX751
TABLE OF CONTENTS
1 PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-22
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29
MENU
KD-SHX751
PICT
SOURCE
DISP
BACK
T/P
BAND
Area suffix
E ------------- Southern Europe
EX ------------ Northern Europe
EY ------------- Eastern Europe
EU ------------------------- Turkey

1-2 (No.MA163)
SPECIFICATION
• Design and specifications are subject to change without notice.
• Microsoft and Windows Media are either registered trademarks or trademarks of Microsoft Corporation in the United States and/
or other countries.
• SD logo is a trademark.
AUDIO AMPLIFIER SECTION
Maximum Power Output Front 52 W per channel
Rear 52 W per channel
Continuous Power Output (RMS) Front 22 W per channel into 4 Ω, 40 Hz to 20 000 Hz at no more than 0.8% total
harmonic distortion.
Rear 22 W per channel into 4 Ω, 40 Hz to 20 000 Hz at no more than 0.8% total
harmonic distortion.
Load Impedance 4 Ω(4 Ωto 8 Ωallowance)
Equalizer Control Range Frequencies 60 Hz, 150 Hz, 400 Hz, 1 kHz, 2.4 kHz, 6 kHz, 12 kHz
Level ±10 dB
Frequency Response 40 Hz to 20 000 Hz
Signal-to-Noise Ratio 70 dB
Line-In Level/Impedance LINE IN 1.5 V/20 kΩload
Line-Out Level/Impedance LINE OUT 5.0 V/20 kΩload (full scale)
Output Impedance 1 kΩ
Other Terminals SUBWOOFER OUT
Changer control
Steering wheel remote input
TUNER SECTION
Frequency Range FM 87.5 MHz to 108.0 MHz
AM (MW) 522 kHz to 1 620 kHz
(LW) 144 kHz to 279 kHz
FM Tuner Usable Sensitivity 11.3 dBf (1.0 µV/75 Ω)
50 dB Quieting Sensitivity 16.3 dBf (1.8 µV/75 Ω)
Alternate Channel Selectivity (400 kHz) 65 dB
Frequency Response 40 Hz to 15 000 Hz
Stereo Separation 35 dB
Capture Ratio 1.5 dB
MW Tuner Sensitivity 20 µV
Selectivity 65 dB
LW Tuner Sensitivity 50 µV
CD/SD PLAYER SECTION
Type Compact disc player
Signal Detection System Non-contact optical pickup (semiconductor laser)
Number of Channels 2 channels (stereo)
Frequency Response 5 Hz to 20 000 Hz
Dynamic Range 98 dB
Signal-to-Noise Ratio 102 dB
Wow and Flutter Less than measurable limit
MP3 (MPEG Audio Layer 3) Max. Bit Rate 320 kbps
WMA (Windows Media Audio) Max. Bit Rate 192 kbps
Playable SD Card Format FAT 12/16
Storage Up to 512 MB
Playable Audio Format for SD Card MP3/WMA
GENERAL
Power Requirement Operating Voltage DC 14.4 V (11 V to 16 V allowance)
Grounding System Negative ground
Allowable Operating Temperature 0°C to +40°C
Dimensions (W ×H ×D) Installation Size (approx.) 182 mm ×52 mm ×157 mm
Panel Size (approx.) 188 mm ×58 mm ×13 mm
Mass (approx.) 1.7 kg (excluding accessories)

(No.MA163)1-3
SECTION 1
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.
!Please use enough caution not to see the beam directly or touch it in case of an
adjustment or operation check.

1-4 (No.MA163)
1.2 Preventing static electricity
Electrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is discharged, can destroy the laser
diode in the traverse unit (optical pickup). Take care to prevent this when performing repairs.
1.2.1 Grounding to prevent damage by static electricity
Static electricity in the work area can destroy the optical pickup (laser diode) in devices such as CD players.
Be careful to use proper grounding in the area where repairs are being performed.
(1) Ground the workbench
Ground the workbench by laying conductive material (such as a conductive sheet) or an iron plate over it before placing the
traverse unit (optical pickup) on it.
(2) Ground yourself
Use an anti-static wrist strap to release any static electricity built up in your body.
(3) Handling the optical pickup
• In order to maintain quality during transport and before installation, both sides of the laser diode on the replacement optical
pickup are shorted. After replacement, return the shorted parts to their original condition.
(Refer to the text.)
• Do not use a tester to check the condition of the laser diode in the optical pickup. The tester's internal power source can easily
destroy the laser diode.
1.3 Handling the traverse unit (optical pickup)
(1) Do not subject the traverse unit (optical pickup) to strong shocks, as it is a sensitive, complex unit.
(2) Cut off the shorted part of the flexible cable using nippers, etc. after replacing the optical pickup. For specific details, refer to the
replacement procedure in the text. Remove the anti-static pin when replacing the traverse unit. Be careful not to take too long a
time when attaching it to the connector.
(3) Handle the flexible cable carefully as it may break when subjected to strong force.
(4) It is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not turn it.
1.4 Attention when traverse unit is decomposed
*Please refer to "Disassembly method" in the text for the CD pickup unit.
• Apply solder to the short land before the flexible wire is disconnected from the connector on the CD pickup unit.
(If the flexible wire is disconnected without applying solder, the CD pickup may be destroyed by static electricity.)
• In the assembly, be sure to remove solder from the short land after connecting the flexible wire.
1M
(caption)
Anti-static wrist strap
Conductive material
(conductive sheet) or iron plate
CN601
Short sections Flexible wire
Mechanism control board

(No.MA163)1-5
1.5 Important for laser products
1.CLASS 1 LASER PRODUCT
2.DANGER : Invisible laser radiation when open and inter
lock failed or defeated. Avoid direct exposure to beam.
3.CAUTION : There are no serviceable parts inside the
Laser Unit. Do not disassemble the Laser Unit. Replace
the complete Laser Unit if it malfunctions.
4.CAUTION : The CD,MD and DVD player uses invisible
laser radiation and is equipped with safety switches which
prevent emission of radiation when the drawer is open and
the safety interlocks have failed or are defeated. It is
dangerous to defeat the safety switches.
5.CAUTION : If safety switches malfunction, the laser is able
to function.
6.CAUTION : Use of controls, adjustments or performance of
procedures other than those specified here in may result in
hazardous radiation exposure.
REPRODUCTION AND POSITION OF LABELS
!
Please use enough caution not to
see the beam directly or touch it
in case of an adjustment or operation
check.
WARNING LABEL
CAUTION : Visible and Invisible
laser radiation when open and
interlock failed or defeated.
AVOID DIRECT EXPOSURE TO
BEAM. (e)
VARNING : Synlig och
osynling laserstrålning när
den öppnas och spärren är
urkopplad. Betrakta ej
strålen. (s)
VARO : Avattaessa ja suojalukitus
ohitettuna tai viallisena olet alttiina
näkyvälle ja näkymättömälle
lasersäteilylle. Vältä säteen
kohdistumista suoraan itseesi. (f)
ADVARSEL : Synlig og usynlig
laserstråling når maskinen er
åben eller interlocken fejeler.
Undgå direkte eksponering til
stråling. (d)
CLASS 1
LASER PRODUCT

1-6 (No.MA163)
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

(No.MA163)1-7
SECTION 3
DISASSEMBLY
3.1 Main body section
3.1.1 Removing the front panel assembly
(See Fig.1)
(1) Push the detach button in the lower right part of the front
panel assembly.
(2) Remove the front panel assembly.
Fig.1
3.1.2 Removing the heat sink
(See Fig.2)
Reference:
Remove the front panel assembly as required.
(1) From the left side of the main body, remove the two screws
Aand two screws Battaching the heat sink.
(2) Remove the heat sink from the main body.
Fig.2
Detach button
Front panel assembly
Heat sink
AAB

1-8 (No.MA163)
3.1.3 Removing the top chassis assembly
(See Figs.3 to 6)
• Prior to performing the following procedures, remove the heat
sink.
Reference:
Remove the front panel assembly as required.
(1) From the bottom side of the main body, remove the two
screws Cattaching the top chassis assembly to the bottom
chassis assembly. (See Fig.3)
(2) From the both and rear sides of the main body, remove the
four screws Dattaching the top chassis assembly to the
bottom chassis assembly. (See Figs.4 to 6)
(3) Remove the screw Eattaching the IC heat sink to bottom
chassis assembly. (See Fig.5)
(4) Lift the top chassis assembly in the direction of the arrow,
disconnect the connector CN503 on the mechanism con-
trol board from the connector CN721 on the main board.
(See Figs.4 to 6)
(5) Take out the top chassis assembly from the bottom chassis
assembly.
Reference:
Remove the screw E' and the IC heat sink as required. (See
Fig5)
Fig.3
Fig.4
Fig.5
Fig.6
Top chassis assembly
C
C
Bottom chassis assembly
Bottom chassis assembly
Top chassis assembly
D
CN503
CN721
Main board
Mechanism control board
Top chassis assembly
D
Bottom chassis assembly
Mechanism control board
E'E
IC heat sink
Top chassis assembly
Bottom chassis assembly Rear bracket
D
D

(No.MA163)1-9
3.1.4 Removing the front chassis assembly
(See Figs.7 and 8)
• Prior to performing the following procedure, remove the front
panel assembly, heat sink and top chassis assembly.
(1) From the both sides of the top chassis assembly, remove
the two screws Fattaching the front chassis assembly.
(2) Remove the front chassis assembly from the top chassis
assembly.
Fig.7
Fig.8
3.1.5 Removing the CD mechanism assembly
(See Fig.9)
• Prior to performing the following procedures, remove the front
panel assembly, heat sink and top chassis assembly.
Reference:
Remove the front chassis assembly as required.
(1) From the inside of the top chassis assembly, remove the
three screws Gattaching the CD mechanism assembly.
(2) Release the mecha heat sink from the slots aon the mech-
anism control board and remove the mecha heat sink from
the main body.
(3) Take out the CD mechanism assembly from the top chas-
sis.
Fig.9
Top chassis assembly
Front chassis assembly
F
Top chassis assembly
Front chassis assembly
F
Top chassis
Mecha heat sink
G
G G
CD mechanism assembly
a
Mechanism control board

1-10 (No.MA163)
3.1.6 Removing the main board
(See Figs.10 and 11)
• Prior to performing the following procedures, remove the front
panel assembly, heat sink and top chassis assembly.
(1) From the rear side of the bottom chassis assembly, remove
the two screws Hattaching the rear bracket to the bottom
chassis assembly. (See Fig.10)
(2) From the top side of the bottom chassis assembly, remove
the two screws Jattaching the main board to the bottom
chassis assembly. (See Fig.11)
(3) Release the stopper of the connector CN701 on the main
board in an upward direction, disconnect the card wire from
the connector CN701. (See Fig.11)
(4) Disconnect the wire from the connector of the front door
mechanism assembly. (See Fig.11)
(5) Disconnect the wire from the connector CN991 on the main
board. (See Fig.11)
Reference:
After connecting the wires, fix the wires with the wire
holders.
(6) Take out the main board from the bottom chassis assem-
bly.
Fig.10
Fig.11
3.1.7 Removing the rear bracket
(See Fig.12)
• Prior to performing the following procedures, remove the front
panel assembly, heat sink, top chassis assembly and main
board.
(1) From the rear side of the main board, remove the wires
from the rear bracket in the direction of the arrow.
(2) Remove the screw K, screw Land four screws Mattaching
the rear bracket to the main board.
Reference:
After attaching the rear bracket to the main board, pass the
wires through the wire holder and insert them into the slots of
the rear bracket.
Fig.12
Rear bracket
H
Bottom chassis assembly
Connector
Wire holders CN701
Stopper
Bottom chassis assembly
J
J
CN991
Main board
Card wire
Front door mechanism assembly
Rear bracket
M
M M
K
Main board
Wire holder
Slots
Rear bracket
Wires
L

(No.MA163)1-11
3.1.8 Removing the front door mechanism assembly
(See Fig.13)
• Prior to performing the following procedures, remove the front
panel assembly, heat sink, top chassis assembly and main
board.
(1) From the top side of the bottom chassis assembly, remove
the screw Nattaching the FPC guide to the bottom chassis.
(2) Remove the five screws Pattaching the front door mecha-
nism assembly to the bottom chassis.
Reference:
When attaching the screws Nand P, apply a locking
agent them.
(3) Take out the front door mechanism assembly from the bot-
tom chassis.
Fig.13
3.1.9 Removing the switch board
(See Figs.14 to 16)
• Prior to performing the following procedures, remove the front
panel assembly.
(1) From the rear side of the front panel assembly, remove the
six screws Qattaching the rear cover to the front panel as-
sembly. (See Fig.14)
(2) Release the two joints bof the front panel assembly and re-
move the rear cover. (See Fig.15.)
(3) Take out the switch board from the front panel assembly.
(See Fig.16)
Note:
When removing the rear cover assembly and switch board, be
careful not to lose the spring. Fig.14
Fig.15
Fig.16
Bottom chassis
PP
N
FPC guide
Front door mechanism assembly
QRear cover assembly
Q
Q
Rear cover assembly
Joints bJoints b
Switch board
Front panel assembly
Spring

1-12 (No.MA163)
3.2 CD mechanism assembly section
• Remove the CD mechanism assembly from the main body.
(See "3.1.5 Removing the CD mechanism assembly".)
3.2.1 Removing the mechanism control board
(See Fig.1)
(1) From the bottom side of the CD mechanism assembly, sol-
der the short sections on the flexible wire.
Caution:
Solder the short sections on the flexible wire before dis-
connecting the flexible wire from the connector CN601
on the mechanism control board. If you do not follow this
instruction, the CD pickup may be damaged.
(2) Disconnect the flexible wire from the connector CN601 on
the mechanism control board.
(3) Disconnect the flexible wire from the connector CN602 on
the mechanism control board.
(4) Remove the solders from the soldered sections aon the
mechanism control board and remove the wires of the feed
motor.
(5) Remove the solders from the soldered sections bon the
mechanism control board, and remove each wire of the
spindle motor and other parts.
(6) Remove the five screws Aattaching the mechanism con-
trol board.
Caution:
When reassembling, remove the solders from the short sec-
tions after connecting the flexible wire to the connector CN601
on the mechanism control board.
Fig.1
A
A
CN601
Short sections
Feed motor
Flexible wire
CD mechanism assembly
A
Mechanism control board
b
Spindle motor
ACN602
A
a

(No.MA163)1-13
3.2.2 Removing the top cover
(See Fig.2)
(1) From the back side of the CD mechanism assembly, re-
move the two screws Battaching the top cover.
(2) Take out the top cover in an upward direction.
Reference:
When attaching the top cover, set the sections cof the top cov-
er under the bending sections dof the chassis base 2.
3.2.3 Removing the mechanism section
(See Figs.2 to 4)
• Remove the mechanism control board and top cover.
(1) From the front side of the CD mechanism assembly, re-
move the two screws Cattaching the right and left stop-
pers. (See Fig.2.)
(2) Remove the two floating springs on the bottom side of the
CD mechanism assembly. (See Fig.3.)
(3) Take out the mechanism section in an upward direction
and remove the three damper springs from the dampers.
(See Fig.4.)
Caution:
• When reassembling the mechanism section, reattach the
damper springs to the dampers respectively and insert the
three shafts on the bottom of the mechanism section to the
dampers. (See Fig.4.)
• Before inserting the shaft to the dampers, apply IPA to the
hole of damper.
Fig.2
Fig.3
Fig.4
B
Top cover
Stopper
Stopper
C
C
B
d
c
Chassis base 2
Floating spring
Mechanism section
Dampe
r
(Yellow)
Damper
(Black)
Damper
(Black)
Damper
spring(F)
(Green)
Damper
spring(F)
(Green)
Damper
spring(R)
(Red)

1-14 (No.MA163)
3.2.4 Removing the clamper unit
(See Figs.5 and 6)
• Remove the mechanism control board, top cover and mecha-
nism section.
(1) From the bottom side of the mechanism section, remove
the clamper 2 spring. (See Fig.5.)
(2) Release section eof the clamper spring from the bending
section of the CD chassis assembly. (See Fig.6.)
(3) Move the clamper unit 2 in the direction of the arrow and
release the joints (f, g). (See Fig.5.)
(4) Take out the clamper unit 2 in an upward direction. (See
Fig.5.)
3.2.5 Reattaching the clamper unit
(See Figs.5 to 9)
(1) From the bottom side of the mechanism section, attach the
clamper spring to the clamper unit 2. (See Figs.5 and 9.)
(2) Move the clamper unit 2 to set the joints (f, g) to each pro-
jection of the CD chassis assembly. (See Fig.5.)
(3) Make sure that section hof the clamper unit 2 is inserted to
the notch of the CD chassis assembly. (See Figs.5 and 8.)
(4) Move the clamper spring to the outside of the bending part
of the CD chassis assembly. (See Fig.6.)
Caution:
When reattaching the clamper unit 2, temporarily hook
the end of the clamper spring as shown in the figure to
make the work easy. (See Fig.9.)
(5) Attach the clamper 2 spring to the CD chassis assembly
and clamper unit 2. (See Figs.5 and 7.)
Fig.5
Fig.6
Clamper unit 2
Clamper spring
Clamper 2 spring
h
f
g
CD chassis assembly
Clamper spring
CD chassis assembly
e

(No.MA163)1-15
Fig.7
Fig.8
Fig.9
CD chassis assembly
Clamper 2 spring
Clamper unit 2
Notch
h
Clamper unit 2
Clamper unit 2
Clamper spring

1-16 (No.MA163)
3.2.6 Removing the front unit
(See Figs10 to 12)
• Remove the mechanism control board, top cover and mecha-
nism section.
(1) From the bottom side of the mechanism section, remove
the double-stick tape fixing the flexible wire. (See Fig.10.)
(2) From the top side of the mechanism section, remove the
screw Dattaching the front unit 2. (See Figs.11 and 12.)
(3) Move the front unit 2 toward the front to release the joint i.
(See Figs.11 and 12.)
(4) Release two joints jand kon the right side of the CD chas-
sis assembly. (See Fig.12.)
(5) Take out the front unit 2 in an upward direction.
(6) Remove the double-stick tape fixing the flexible wire and
remove the two screws Eattaching the switch wire. (See
Fig.12.)
Reference:
You can remove the switch wire only without removing the
front unit 2.
Fig.10
Fig.11
Fig.12
Flexible wire
Double-stick tape
D
Front unit 2
i
i
Front unit 2
Switch wire
j
D
E
k
Double-stick tape
CD chassis assembly
Flexible
wire

(No.MA163)1-17
3.2.7 Removing the loading arm assembly
(See Figs.13 and 14)
• Remove the mechanism control board, top cover, mechanism
section and front unit 2.
(1) From top side of the mechanism section, move the loading
arm assembly in the direction of the arrow. (See Fig.13.)
(2) Release the projections from the right and left joints (m, n)
of the CD chassis assembly. (See Figs.13 and 14.)
(3) Release the projection from notch pof the connect arm on
the right side of the mechanism section and release the
projection from notch qof the slide cam assembly on the
left side. (See Figs.13 and 14.)
Fig.13
Fig.14
m
p
n
Loading arm assembly
CD chassis assembly
mp
n
Loading arm assembly
q
Side cam
assembly
Connect arm
CD chassis assembly

1-18 (No.MA163)
3.2.8 Removing the rod (L), rod (R) and roller assembly
(See Figs.15 and 16)
• Remove the mechanism control board, top cover, mechanism
section, front unit and loading arm assembly.
(1) From the bottom side of the loading arm assembly, release
the rod (L) and (R) from the joints r. (See Fig.15.)
(2) Remove the roller assembly from the loading arm assem-
bly. (See Fig.16.)
(3) Remove the two collars and washer from the roller assem-
bly. (See Fig.16.)
Caution:
After attaching the roller assembly to the loading arm assem-
bly, attach the rod (L) and (R). Then attach the rods to the right
and left collars of the roller assembly. (See Fig.15.)
Fig.15
Fig.16
r
rr
r
Rod(R)
Loading arm assembly
Rod(L)
Collar Collar
Rod(R) Rod(L)
Roller assembly
Roller assembly
Washer
Collar
Collar
Rod(L)
Loading arm assembly
Rod(R)

(No.MA163)1-19
3.2.9 Removing the CD pickup
(See Figs.17 to 19)
• Remove the mechanism control board.
(1) From the bottom side of the CD mechanism assembly, turn
the feed gear in the direction of the arrow to move the CD
pickup assembly outwards. (See Fig.17.)
(2) Remove the screw Fand remove the thrust spring. (See
Fig.17.)
(3) Remove the CD pickup assembly in an upward direction
from the side of L.S. gear and release the CD pickup as-
sembly from joint s of the sub guide. (See Fig.18.)
(4) Move the lead screw of the CD pickup assembly in the di-
rection of the arrow to release at joint t. (See Fig.18.)
(5) Remove the screw Gattaching the CD rack spring and CD
rack plate on the CD pickup assembly. (See Fig.19.)
(6) Pull out the lead screw. (See Fig.19.)
Caution:
• When attaching the CD pickup assembly, attach the CD
pickup assembly at joint sof sub guide first, and attach the
lead screw to the joint ton the L.S.holder 2. (See Fig.18.)
• Perform electric adjustment after replacing the pickup.
Fig.17
Fig.18
Fig.19
F
Feed gear
Thrust spring
CD pickup assembly
CD mechanism assembly
s
t
L.S.holder 2
L.S. Gear
Lead screw
CD Pickup assembly
Sub guide
G
CD rack spring
CD rack plate
CD Pickup
Lead screw

1-20 (No.MA163)
3.2.10 Removing the spindle motor
(See Fig.20)
• Remove the mechanism control board, top cover, mechanism
section and clamper unit.
(1) From the top side of the mechanism section, remove the
T.table assembly and washer from the spindle motor.
(2) Remove the two screws Hattaching the spindle motor.
(3) Take out the spindle motor from the bottom side of the
mechanism section.
Caution:
Perform adjustment when reattaching the spindle motor.
Fig.20
3.2.11 Removing the feed motor
(See Figs.21 and 22)
• Remove the mechanism control board.
(1) From the bottom side of the CD mechanism assembly, re-
move the feed TRI. spring. (See Fig.21.)
(2) Remove the two screws Jattaching the feed motor assem-
bly. (See Fig.21.)
(3) Remove the slit washer from the motor H. assembly and
pull out the worm wheel. (See Fig.22.)
(4) Remove the two screws Kattaching the feed motor. (See
Fig.22.)
Fig.21
Fig.22
Washer H
T. table assembly
Spindle moto
r
J
Feed motor assembly
Feed TRI. spring
Feed moto
r
Motor H. assembly
Worm wheel
K
Slit washer