JVC TH-M301, TH-M303 Service Manual
SERVICE MANUAL
DVD DIGITAL THEATER SYSTEM
MB18420043
TH-M303, TH-M301
TH-M303
Area suffix
J ----------------------------- U.S.A.
C -------------------------- Canada
TH-M301
Area suffix
J ----------------------------- U.S.A.
TABLE OF CONTENTS
1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-33
COPYRIGHT © 2004 VICTOR COMPANY OF JAPAN, LIMITED
No.MB184
2004/3
SPECIFICATION
Center unit (XV-THM606/XV-THM603/XV-THM505/XV-THM501/ XV-THM303/XV-THM301)
Audio section Total Harmonic Distortion 0.02%
NOTE This value is measured at System cord CONNECTOR for reference.
Digital input *1 DIGITAL IN (DBS) (OPTICAL):
Video section
Tuner section Tuning Range FM:87.5 MHz to 108.0 MHz
General Power Consumption 18 W (at operation) 2.0 W (in standby mode)
Video System NTSC
Horizontal Resolution 500 lines
Signal-to-Noise Ratio 64 dB
Video output level Composite:1.0 V(p-p)/75Ω
Video input sensitivity/Impedance
(VCR IN)
Power Requirements AC 120 V, 60 Hz
Dimensions (W × H × D) 400 mm × 85 mm × 380 mm (15-3/4 inches × 3-3/8 inches × 15 inches)
Mass 4.3 kg (9.5 lbs)
*1: Corresponding to Linear PCM, Dolby Digital, and DTS Digital Surround (with sampling frequency - 32 kHz, 44.1 kHz, 48 kHz)
Subwoofer (SP-PWM603/SP-PWM303/SP-PWM301)
Amplifier section Front/Center/Surround 115 W (100 W *3) per channel, RMS at 4 Ω (Center/Surround)/ 125 W (115 W *3) per channel,
Subwoofer 125 W (120 W *3), RMS at 4 Ω at 100 Hz, with 10 % total harmonic distortion.
Speaker section Speaker unit 16 cm (6-5/16 inches) Bass-reflex, Magnetically Shielded
Frequency Range 30 Hz to 200 Hz
General Power Requirements AC 120 V, 60 Hz
Power Consumption 125 W (at operation) 0 W (in standby mode)
Dimensions (W × H × D) 168.5 mm × 412 mm × 444 mm (6-11/16 inches × 16-1/4 inches × 17-1/2 inches)
Mass 12.0 kg (26.5 lbs)
*3: For SP-PWM301
Front speakers (SP-THM303F)
Speakers 8.0 cm (3-3/16 inches) Bass-reflex, Magnetically Shielded
Power Handling Capacity 140 W
Impedance 4Ω
Frequency Range 90 Hz to 20 kHz
Dimensions (W × H × D) 106 mm × 119.5 mm × 102 mm (4-3/16 inches × 4-3/4 inches × 4-1/16 inches)
Mass 0.69 kg (1.6 lbs)
-21 dBm to -15 dBm (660 nm E30 nm)
S-video-Y:1.0 V(p-p)/75Ω
S-video-C:0.286 V(p-p)/75Ω
Component-Y:1.0 V(p-p)/75Ω
Component-PB/PR:0.7 V(p-p)/75Ω
Composite:1.0 V(p-p)/75Ω
S-video-Y:1.0 V(p-p)/75Ω
S-video-C:0.286 V(p-p)/75Ω
AM:530 kHz to 1 710 kHz
RMS at 4 Ω (Front) at 1 kHz, with 10 % total harmonic distortion.
Surround speakers (SP-THM303S)
Speakers 8.0 cm (3-3/16 inches) Bass-reflex, Magnetically Shielded
Power Handling Capacity 140 W
Impedance 4Ω
Frequency Range 80 Hz to 20 kHz
Dimensions (W × H × D) 111.5 mm × 139 mm × 106.5 mm (4-7/16 inches × 5-1/2 inches × 4-1/4 inches)
Mass 0.63 kg (1.4 lbs)
Center Speaker (SP-THM303C)
Speakers 8.0 cm (3-3/16 inches) Bass-reflex, Magnetically Shielded
Power Handling Capacity 140 W
Impedance 4Ω
Frequency Range 90 Hz to 20 kHz
Dimensions (W × H × D) 106 mm × 119.5 mm × 102 mm (4-3/16 inches × 4-3/4 inches × 4-1/16 inches)
Mass 0.69 kg (1.6 lbs)
Designs & specifications are subject to change without notice.
1-2 (No.MB184)
SECTION 1
PRECAUTION
1.1 Safety Precautions
(1) This design of this product contains special hardware and
many circuits and components specially for safety purposes. For continued protection, no changes should be made
to the original design unless authorized in writing by the
manufacturer. Replacement parts must be identical to
those used in the original circuits. Services should be performed by qualified personnel only.
(2) Alterations of the design or circuitry of the product should
not be made. Any design alterations of the product should
not be made. Any design alterations or additions will void
the manufacturers warranty and will further relieve the
manufacture of responsibility for personal injury or property
damage resulting therefrom.
(3) Many electrical and mechanical parts in the products have
special safety-related characteristics. These characteristics are often not evident from visual inspection nor can the
protection afforded by them necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special
safety characteristics are identified in the Parts List of Service Manual. Electrical components having such features
are identified by shading on the schematics and by ( ) on
the Parts List in the Service Manual. The use of a substitute
replacement which does not have the same safety characteristics as the recommended replacement parts shown in
the Parts List of Service Manual may create shock, fire, or
other hazards.
(4) The leads in the products are routed and dressed with ties,
clamps, tubings, barriers and the like to be separated from
live parts, high temperature parts, moving parts and/or
sharp edges for the prevention of electric shock and fire
hazard. When service is required, the original lead routing
and dress should be observed, and it should be confirmed
that they have been returned to normal, after reassembling.
(5) Leakage shock hazard testing
After reassembling the product, always perform an isolation check on the exposed metal parts of the product (antenna terminals, knobs, metal cabinet, screw heads,
headphone jack, control shafts, etc.) to be sure the product
is safe to operate without danger of electrical shock.Do not
use a line isolation transformer during this check.
• Plug the AC line cord directly into the AC outlet. Using a
"Leakage Current Tester", measure the leakage current
from each exposed metal parts of the cabinet, particularly any exposed metal part having a return path to the
chassis, to a known good earth ground. Any leakage current must not exceed 0.5mA AC (r.m.s.).
• Alternate check method
Plug the AC line cord directly into the AC outlet. Use an
AC voltmeter having, 1,000
in the following manner. Connect a 1,500
paralleled by a 0.15
exposed metal part and a known good earth ground.
Measure the AC voltage across the resistor with the AC
Ω per volt or more sensitivity
Ω 10W resistor
µF AC-type capacitor between an
voltmeter.
Move the resistor connection to each exposed metal
part, particularly any exposed metal part having a return
path to the chassis, and measure the AC voltage across
the resistor. Now, reverse the plug in the AC outlet and
repeat each measurement. Voltage measured any must
not exceed 0.75 V AC (r.m.s.). This corresponds to 0.5
mA AC (r.m.s.).
AC VOLTMETER
(Having 1000
ohms/volts,
or more sensitivity)
0.15 F AC TYPE
Place this
probe on
1500 10W
Good earth ground
1.2 Warning
(1) This equipment has been designed and manufactured to
meet international safety standards.
(2) It is the legal responsibility of the repairer to ensure that
these safety standards are maintained.
(3) Repairs must be made in accordance with the relevant
safety standards.
(4) It is essential that safety critical components are replaced
by approved parts.
(5) If mains voltage selector is provided, check setting for local
voltage.
1.3 Caution
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 Critical parts for safety
In regard with component parts appearing on the silk-screen
printed side (parts side) of the PWB diagrams, the parts that are
printed over with black such as the resistor ( ), diode ( )
and ICP ( ) or identified by the " " mark nearby are critical
for safety. When replacing them, be sure to use the parts of the
same type and rating as specified by the manufacturer.
(This regulation dose not Except the J and C version)
each exposed
metal part.
(No.MB184)1-3
1.5 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.
1.5.1 Grounding to prevent damage by static electricity
Static electricity in the work area can destroy the optical pickup (laser diode) in devices such as laser products.
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.
(caption)
Anti-static wrist strap
1M
Conductive material
(conductive sheet) or iron palate
(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.
1.6 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) I t is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not turn it.
1.7 Attention when traverse unit is decomposed
*Please refer to "Disassembly method" in the text for the pickup unit.
• Apply solder to the short land sections before the flexible wire is disconnected from the connecto on the servo board. (If the flexible
wire is disconnected without applying solder, the pickup may be destroyed by static electricity.)
• In the assembly, be sure to remove solder from the short land sections after connecting the flexible wire.
Short circuit points
1-4 (No.MB184)
1.8 Importance administering point on the safety
F901
1.6A-125V
Power board
Caution: For continued protection against risk of
fire, replace only with same type 1.6A/125V for
F901.
This symbol specifies type of fast operating fuse.
Precaution: Pour eviter risques de feux, remplacez
le fusible de surete de F901 comme le meme type
que 1.6A/125V.
Ce sont des fusibles suretes qui functionnes rapide.
^
(No.MB184)1-5
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.
1-6 (No.MB184)
SECTION 3
r
DISASSEMBLY
3.1 Main body section
3.1.1 Removing the metal cover
(See Figs.1 to 4)
(1) From the both sides of the main body, remove the four
screws A attaching the metal cover. (See Figs.1 and 2)
(2) From the back side of the main body, remove the three
screws B attaching the metal cover. (See Fig.3)
(3) Lift the rear section of the metal cover in the direction of the
arrow while extending the lower sections of the metal cover, release the five claws a using a longer screwdriver from
the inside as required. (See Fig.4)
Note:
Do not damage any parts and boards inside the main body
when releasing the claws a using a longer screwdriver.
Metal cover
A
Fig.1
Metal cover
A
Fig.2
B
Fig.3
Claws a Claws a
Metal cove
Metal cover
Fig.4
(No.MB184)1-7
3.1.2 Removing the front panel assembly
(See Figs.5 and 6)
• Prior to performing the following procedures, remove the metal
cover.
(1) From the top side of the main body, disconnect the parallel
wires from the connectors (CN456
board. (See Fig.5)
(2) Disconnect the card wires from the connectors (CN450
) on the main board. (See Fig.5)
CN460
(3) Remove the screw C attaching the earth wire to the main
board. (See Fig.5)
Reference:
When attaching the screw C, attach the earth wire with
it. (See Fig.5)
(4) From the bottom side of the main body, remove the three
screws D attaching the front panel assembly. (See Fig.6)
(5) From the both and bottom sides of the main body, remove
the front panel assembly in the direction of the arrow while
releasing the joints b and c. (See Fig.6)
, CN457) on the main
Main board
,
CN456
CN450
CN457
CN460
C
Earth
wire
Card wire
Front panel assembly
Front panel assembly
Fig.5
Joint c Joint bJoint b
Parallel wires
Card wire
D
1-8 (No.MB184)
Fig.6
3.1.3 Removing the DVD changer mechanism assembly
(See Fig.7)
• Prior to performing the following procedures, remove metal
cover and front panel assembly.
(1) From the top side of the main body, disconnect the card
wires from the connectors (CN401
board.
Reference:
When connecting the card wires, connect them to the
connectors (CN401
passing the card wires through the hole d on the main
board.
(2) Remove the four screws E attaching the DVD changer
mechanism assembly on the bottom chassis.
(3) Take out the DVD changer mechanism assembly in the up-
ward direction.
Reference:
When attaching the DVD changer mechanism assembly, align
the holes of the DVD changer mechanism assembly to the projections e on the bottom chassis.
to CN403) on the main board after
to CN403) on the main
E
DVD changer mechanism assembly
Projections e
E
CN402
CN401
CN403
3.1.4 Removing the rear panel
(See Fig.8)
• Prior to performing the following procedures, remove the metal
cover.
(1) From the back side of the main body, remove the screw F
and twelve screws G attaching the rear panel.
E
Card wires
Hole d
Fig.7
Main board
Bottom chassis
FG
G
Fig.8
Rear panel
(No.MB184)1-9
3.1.5 Removing the audio & digital input board
(See Figs.9 and 10)
• Prior to performing the following procedures, remove the metal
cover.
(1) From the top side of the main body, disconnect the card
wires from the connectors (CN411
board. (See Fig.9)
(2) Remove the screw H attaching the audio & digital input
board to the bracket(DSP). (See Fig.9)
(3) From the back side of the main body, remove the screw J
and two screws K attaching the audio & digital input board
to the rear panel. (See Fig.10)
(4) Take out the audio & digital input board from the main
body.
, CN412) on the main
Main board
Card wires
Bracket
(DSP)
CN412
CN411
M
Power supply board
3.1.6 Removing the tuner
(See Figs.9 and 10)
• Prior to performing the following procedures, remove the metal
cover.
(1) From the top side of the main body, disconnect the card
wire from the connector CN1
(2) From the back side of the main body, remove the two
screws L attaching the tuner to the rear panel. (See Fig.10)
(3) Take out the tuner from the main body.
3.1.7 Removing the power supply board
(See Figs.9 and 10)
• Prior to performing the following procedures, remove the metal
cover.
(1) From the top side of the main body, disconnect the parallel
wires from the connectors (CN404
board. (See Fig.9)
(2) Remove the three screws M attaching the power supply
board. (See Fig.9)
(3) From the back side of the main body, remove the screw N
attaching the power supply board to the rear panel. (See
Fig.10)
(4) Take out the power supply board from the main body.
Reference:
Remove the rear panel as required. (See removing the rear
panel)
on the tuner. (See Fig.9)
to CN407) on the main
H
CN407
CN406
CN1
Card wire
Audio & digital input board
JN
CN405
Tuner
KL
M
CN404
Parallel wires
Fig.9
Rear panel
Fig.10
1-10 (No.MB184)
3.1.8 Removing the main board
f
(See Fig.11)
• Prior to performing the following procedures, remove the metal
cover, rear panel, audio & digital input board and tuner.
(1) From the top side of the main body, disconnect the card
wires from the connectors (CN401
) on the main board.
CN460
Reference:
When reassembling, connect the card wires to the connectors (CN401
ing the card wires through the hole f on the main board.
(2) Disconnect the parallel wires from the connectors (CN404
to CN407, CN456 and CN457) on the main board.
(3) From the top side of the main body, remove the two screws
P and screw P' attaching the main board on the bottom
chassis.
Reference:
When attaching the screw P', attach the earth wire with
it. (See Fig.11)
(4) Take out the main board from the main body.
to CN403) on the main board after pass-
to CN403, CN450 and
Earth wire
P'
CN450
P
CN403
CN460 CN456
CN457
P
CN402CN401 Hole
Main board
Bottom chassis
CN407
Fig.11
CN404
CN406
CN405
(No.MB184)1-11
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