JVC THA-30 Service manual

SERVICE MANUAL

DVD DIGITAL CINEMA SYSTEM

Area suffix

TH-A30

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TH-A30

SP-XSA30 2

STANDBY/ON

AUDIO

VCR

TV/VIDEO PROGRESSIVE

TV CHANNEL

DISPLAY

STEP

AUDIO/

SUBTITLE

TV VOLUME

FM MODE

VCR

DVD FM/AM AUX

CONTROL

TUNER PRESET

DOWN UP

REW

VCR CHANNEL

TUNING

B.SEARCH F.SEARCH

ENTER

VOLUME

MUTING

TOP MENU

RETURN

STANDB

RM-STHA30U

DVD CINEMA SYSTEM

STANDBY/ON

AUDIO/FM MOD

Contents

Safety precautions Preventing static electricity Important for laser products

SP-XA30 3

OLUME

SOURCE

DVD DIGITAL CINEMA

SYSTEM TH-A

DIGITAL

XV-THA30 SP-WA30

1-2 1-3 1-4

Disassembly method Wiring connection Description of major ICs

1-5 1-12 1-13~28

No.21172

Dec. 2002

TH-A30

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 manufacturer`s 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 re-assembling.

5. Leakage currnet check (Electrical shock hazard testing) After re-assembling 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 ohms per volt or more sensitivity in the following manner. Connect a 1,500 10W resistor paralleled by a 0.15 F AC-type capacitor between an exposed metal part and a known good earth ground. Measure the AC voltage across the resistor with the AC voltmeter. Move the resistor connection to each exposed metal part, particularly any exposed metal part having a return path to the chassis, and meausre 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.).

0.15 F AC TYPE

1500 10W

Good earth ground

AC VOLTMETER (Having 1000 ohms/volts, or more sensitivity)

Place this probe on each exposed metal part.

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 m ust 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.

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.

In regard with component parts appearing on the silk-screen pr inted 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.

(This regulation does not correspond to J and C version.)

1-2

Preventing static electricity

TH-A30

1.Grounding to prevent damage by 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.

2.About the earth processing for the destruction prevention 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.

2-1 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.

2-2 Ground yourself

Use an anti-static wrist strap to release any static electricity built up in your body.

(caption) Anti-static wrist strap

Conductive material (conductive sheet) or iron plate

3. Handling the optical pickup

1. 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.)

2. 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.

4.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.

Attention when traverse unit is decomposed

*Please refer to "Disassembly method" in the text for pick-up and how to detach the substrate.

Solder is put up before the card

1. wire is removed from connector on the pick up board as shown in Figure. (When the wire is removed without putting up solder, the CD pick-up assembly might destroy.) Please remove solder after

2. connecting the card wire with when you install picking up in the substrate.

DVD mechanism assembly (bottom side)

DVD loading mechanism

Pick up board

Card wire

Short land

(These two points are soldered respectively, and are made to short-circuit)

Connector

DVD loader board

1-3

TH-A30

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 compact disc 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 de feated. 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 herein may result in hazardous radiation exposure.

Please use enough caution not to see the beam directly or touch it in case of an adjustment or operation check.

REPRODUCTION AND POSITION OF LABELS

CLASS 1 LASER PRODUCT

1-4

TH-A30

Disassembly method

Removing the top cover (See Fig.1)

Remove the four screws A attaching the top cover on both sides of the body.

Remove the three screws B on back of the body.

Remove the top cover from behind in the direction of the arrow while pulling both sides outward.

Removing the front panel assembly

(See Fig.2A, 2B and 3)

Prior to performing the following procedure, remove the top cover.

Remove the three screws C attaching the front panel assembly on bottom of the body.

Remove the two screws D attaching the front panel assembly on both sides of the body.

Remove the claw1, claw2 and claw3, and detach the front panel assembly toward the front.

Top cover

Claw1

(bottom side)

(both sides)

Front panel assembly

Fig.1

Fig.2A

Front panel assembly

Claw3

Disconnect the card wire from the connector FCW1 and FCW2 on the display board.

Removing the power cord (See Fig.4)

Prior to performing the following procedure, remove the top cover.

Cut off the tie band fixing the power cord.

Disconnect the power cord from the connector ACW1 on the main board and pull up the cord stopper upward.

Notes : The power cord is exchangeable.

Power cord

ACW1

Claw2

(both sides)

Display board

Front panel assembly

(Inner side)

Fig.2B

FCW1FCW2

Rear panel

Fig.4

Tie band

Power cord

stopper

Fig.3

1-5

TH-A30

Removing the DVD mechanism assembly (See Fig.5 and 6)

Prior to performing the following procedure, remove the top cover.

Disconnect the card wire from the connector J14 and J21 on the DVD MPEG board.

Remove the two screws E attaching the DVD mechanism assembly and pull up with drawing out.

Disconnect the harness from the connector DJ6 on the DVD loader board.

Removing the rear panel (See Fig.7 and 8)

Prior to performing the following procedure, remove the top cover and power cord stopper.

Disconnect the harness from the connector J9 on the DSP board.

Remove the two screws F, four screws G, one screw I and five screws J attaching the each board to the rear panel.

Rear panel

DVD mechanism assembly

Fig.5

DVD mechanism assembly

DVD MPEG board

J14

J21

Remove the three screws K attaching the rear panel on back of the body.

Removing the tuner pack (See Fig.7 and 8)

Prior to performing the following procedure, remove the top cover.

Disconnect the card wire from the connector CON01 on the tuner pack.

Remove the two screws F attaching the tuner pack to the rear panel.

Removing the jack board (See Fig.7 and 8)

Prior to performing the following procedure, remove the top cover.

Disconnect the card wire from the connector VW2 on the jack board.

Disconnect the harness from the connector J10 on the DSP board.

Remove the four screws G attaching the jack board to the rear panel.

Fan motor

DSP board)

DJ6

J10 (on the

Fig.6

Fig.7

DSP board

DVD loader board

Rear panel

GHI

KKK

Removing the fan motor (See Fig.7 and 8)

Prior to performing the following procedures, remove the top cover .

Disconnect the harness from the connector J9 on the DSP board .

Removing the two screws H attaching the fan motor to the rear panel.

1-6

Rear panel

J9(on the

DSP board)

Fig.8

VW2

CON01

Tuner pack

Jack board

TH-A30

Removing the DSP board (See Fig.9)

Prior to performing the following procedure, remove the top cover, front panel assembly, DVD mechanism assembly and jack board.

Remove the harness band fixing the harness.

Disconnect the harness from the connector J9 and J10 on the DSP board.

Disconnect the card wire from the connector J1 and J3 on the DSP board.

Remove the one screw L attaching the DSP board.

Remove the screw M1 and remove the earth wire.

Remove the one screw I attaching the DSP board to the rear panel (see fig.7).

Pull up the DSP board from the front side upwards disconnecting the connector J2, J5, J6 and J7.

Removing the main board (See Fig.10)

Prior to performing the following procedure, remove the top cover, front panel assembly, power cord, DVD mechanism assembly, jack board and DSP board.

Disconnect the card wire from the connector CW8 on the main board.

Disconnect the harness from the connector ACW2, ACW3, ACW4 and ACW5 on the main board.

Harness band

J10

(Rear panel side)

Main board

ACW2

CW8

(fixing the earth wire)

DSP board

J5 J7

Fig.9

J1J3

(Front panel side)

Heat sink1

Heat sink2

ACW3

Remove the five screws J attaching the speaker terminals and jack to the rear panel (see fig.7).

Remove the nine screws M2 attaching the main board.

When the rear panel is not removed, pull up the main board from front side.

Removing the power transistor & power IC (See Fig.10 to 12)

Prior to performing the following procedure, remove the top cover, front panel assembly, DVD mechanism assembly, jack board, DSP board and main board.

After removing the solder part 1 soldered to the main board, remove each screw and remove the heat sink from the power transistor.

After removing the solder part 2 soldered to the main board, remove each screw and remove the heat sink from the power IC.

Heat sink3

Fig.10

(Each power transistor is fixed)

Solder part 1

Solder part 3

Solder part 2 (Power IC is fixed)

(Power IC is fixed)

Fig.11

ACW5

ACW4

Main board (Reverse side )

1-7

TH-A30

The power ICs fixed to the heat sink 3 can be removed individually that it is easy to remove screws (in meaning that a screw driver reaches). It is not necessary to remove whole like abovementioned 1. and 2. . After removing each screw which is fixing each power IC to the heat sink 3, the solder part 3 to which it corresponds on the main board is removed.

In addition, probably, the way after removing the whole will be safe when a screw driver does not reach too.

Removing the power transformer (See Fig.13)

Prior to performing the following procedure, remove the top cover.

Cut off the tie band fixing the harness, if needed.

Disconnect the harness from the connector ACW2 (see fig.10), ACW3, ACW4 and ACW5 on the main board.

Remove the four screws N attaching the power transformer.

Removing the display board & switch board (See Fig.1 and 2)

Prior to performing the following procedure, remove the top cover and the front panel assembly.

Heat sink 3 (to which power IC is attached)

Heat sink 2 (to which power IC is attached)

Heat sink 1 (to which power transistor is attached)

Tie band

Display board

FCW2

Screws

FCW1

Fig.12

ACW4 ACW3

ACW5

Power transformer

Fig.13

Front panel assembly

(inner side)

Switch board

Disconnect the card wire from the connector FCW1 and FCW2 on the display board.

Remove the five screws A attaching the display board on the inner of the front panel assembly.

Remove the four screws B attaching the switch board on the inner of the front panel assembly.

Disconnect the harness from connector FW2 on the display board, if needed.

Removing the front window (See Fig.2 and 3)

Prior to performing the following procedure, remove the top cover, front panel assembly, display board and switch board.

Remove the switch buttons, if needed.

1. Remove the three screws C attaching the front

2. window on the front panel.

Remove the eight claws fixing the front window on

3. the front panel.

1-8

FW2

Fig.1

Front panel assembly

(inner side)

Switch button

CCC

Claw

Fig.2

Front panel assembly

Front window

Fig.3

(front side)

TH-A30

)

Removing the DVD loader board (See Fig.1 to 3)

Prior to performing the following procedure, remove the top cover and DVD mechanism assembly.

Disconnect the card wire from the connector J6 on the DVD MPEG board.

Disconnect the harness from the connector on the motor board.

Disconnect the harness from the connector MJ5 on the DVD loader board.

Remove the four screws A attaching the DVD loader board to DVD mechanism assembly.

CAUTION!! (see fig.3) Before removing the card wire which

connects the pickup board and DVD loader board, solder the two soldering parts and make it short-circuit. Moreover, while having removed the card wire, don't remove these solder.

DVD MPEG board

DVD loader board

RCN1

MJ5

DVD mechanism assembl

Fig.1

DVD mechanism assembl

Motor board

Connector

Fig.2

(top side)

(bottom side

Disconnect the card wire from the connector RCN1 on the DVD loader board.

ONE POINT

How to eject the DVD tray manually (see fig.2)

The white lever of the mark is moved in the direction of the arrow. Then, the tray will be opened. Moreover, the tray is separable from a DVD mechanism assembly by removing two screws of the mark (see fig.1) and drawing out the tray.

Removing the DVD loading mechanism (See Fig.4)

Prior to performing the following procedure, remove the top cover, DVD mechanism assembly and DVD loader board.

Remove the two screws B and remove the bracket.

Remove the one screw C fixing the DVD loading mechanism.

Pick up

board

Lever

Soldering parts

Motor board

Fig.3

DVD mechanism assembl

DVD loading

mechanism

(bottom side)

Bracket

DVD loading

mechanism

Move the lever in the direction of the arrow X.

Remove the DVD loading mechanism from the DVD mechanism assembly by moving it in the direction of the arrow Y.

Fig.4

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