JVC THA-10 Service manual

SERVICE MANUAL

DVD DIGITAL THEATER SYSTEM

TH-A10

SP-PWA10

TH-A10TH-A10

TH-A10

SP-XSA10

(DVD player)/XV-TH-A10

SP-THA10

(Speaker section)

XV-THA10

SP-XCA10

SP-PWA10 (Powered subwoofer) SP-XCA10 (Center speaker)

SP-XSA10 (Satellite speaker) x 4

SP-XSA10

Area Suffix

TH-A10

Maiaysia, Thailand,

Philippines

Brazil, Mexico, Peru

Contents

Safety precautions Preventing static electricity Dismantling and assembling the traverse unit Disassembly method

1-2 1-3

1-4 1-5

Disassembly method Main adjustment Precautions for service Description of major ICs

1-17 1-21 1-24 1-25

No.20890

JAN. 2001

TH-A10

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 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 eachexposed 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.

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.

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.

1-2

CAUTION

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.

1.1. Grounding to prevent damage by static electricity

Static electricity in the work area can destroy the optical pickup (laser diode) in devices such as DVD players. Be careful to use proper grounding in the area where repairs are being performed.

1.1.1. Ground the workbench

1. 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.

1.1.2. Ground yourself

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

TH-A10

(caption) Anti-static wrist strap

Conductive material (conductive sheet) or iron plate

1.1.3. 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.

1.2. 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

1-3

TH-A10

Dismantling and assembling the traverse unit

1. Notice regarding replacement of optical pickup

(Refer to the section regarding anti-static measures.)

1. Do not touch the area around the laser diode and actuator.

2. Do not check the laser diode using a tester, as the diode may easily be destroyed.

3. It is recommended that you use a grounded soldering iron when shorting or removing the laser diode. Recommended soldering iron: HAKKO ESD-compatible product

4. Solder the land on the optical pickup's flexible cable. Note : Short the land after shorting the terminal on the flexible cable using a clip, etc., when using an ungrounded soldering iron. Note : After shorting the laser diode according to the procedure above, remove the solder according to the text explanation.

Short circuit land

Laser pick-up unit

Flexible cable

Shorting

Shot with the rclip

1-4

TH-A10

Disassembly method

Removing the top cover

(See Fig.1 and 2)

Remove the four screws A attaching the top cover (Use an Allen wrench).

Lift up the front part of the top cover to release the two joints a and remove the top cover toward the front.

Removing the rear cover (See Fig. 3)

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

Remove the four screws B attaching the rear cover on the back of the body. Pull out the rear cover backward.

Joints a

Top cover

Fig.1

Top cover

Removing the right and left side covers

(See Fig. 4 and 5)

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

Move the left side cover backward to release the five joint hooks b and remove the left side cover outward.

Remove the right side cover in the same way.

Right side cover

Joint a

Fig.2

Rear cover

Fig.3

Left side cover

Joints b

Fig.4Fig.5

1-5

TH-A10

Removing the front panel assembly

(See Fig. 6 to 9)

Prior to performing the following procedure, remove the top cover, the rear cover and the side covers.

Disconnect the harness from connector CN802 on the main board on the upper side of the body.

Remove the two screws C on the upper side of the body.

Remove the three screws D on the bottom of the body.

Release the five joints c and detach the front panel assembly toward the front.

Joint c

CN802

Front panel assembly

Fig.6

Joint c

Front panel assembly

Joint c

Fig.7

Joint c

1-6

Front panel assembly

Fig.8Fig.9

Removing the right and left corner covers (See Fig.10 and 11)

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

It is not necessary to remove the front panel assembly.

Move the left corner cover backward to release the three joint hooks d.

Remove the right corner cover in the same way.

Removing the rear panel

(See Fig.12 to 14)

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

Remove the eighteen screws E and the one screw F attaching the rear panel.

Left corner cover

Joint d

Joints d

TH-A10

Joints d

Fig.10

Joint d

Right corner cover

Fig.11

Release the two joints e on both sides of the body.

Joint e

Fig.12

Rear panel

Joint e

Rear panel

Fig.12Fig.12

1-7

TH-A10

Removing the DVD servo control board

(See Fig.15 to 17)

Prior to performing the following procedure, remcover and the right side cover.ove the top cover, the rear

Remove the three screws G and pull the DVD servo control board case upward.

Disconnect the harness from connector CN501 and CN503, and the card wire from CN101, CN103 and CN502 of the DVD servo control board on the underside of the DVD servo control board case.

Remove the four screws H attaching the DVD servo control board.

Digital I / O board

CN687

CN501

Analog I / O board

CN681

CN201

DVD servo control board (case)

Fig.15

CN503

CN502

DVD servo control board case

DVD servo control board

DVD servo control board case

CN103

Fig.16

Fig.17

CN101

1-8

TH-A10

Removing the analog I / O board / the digital I / O board (See Fig.18 and 19)

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

Remove the two screws E attaching the analog I / O board on the back of the body.

Disconnect the card wire from connector CN201 on the analog I / O board.

Remove the four screws E attaching the digital I / O board on the back of the body.

Disconnect the card wire from connector CN681 and CN687 on the digital I / O board.

Removing the tuner board / the sub board (See Fig.20 and 21)

Digital I / O board

CN687

Analog I / O board

CN681

CN201

DVD servo control board (case)

Fig.18

Rear panel

Prior to performing the following procedure, remove the top cover, the rear cover and the DVD servo control board case.

Remove the two screws E attaching the tuner board on the back of the body.

Disconnect connector CN111 on the tuner board from the sub board.

Disconnect connector CN131 on the sub board from the main board.

Sub board

CN111

Fig.19

Tuner board

CN131

Fig.20Fig.21

1-9

TH-A10

Removing the DVD mechanism assembly

(See Fig.22 and 23)

Prior to performing the following procedure, remove the top cover, the rear cover, the front panel assembly, the DVD servo control board case, the analog I / O board, the digital I / O board and the tuner board.

Disconnect the harnesses from the spacer on the upper side of the DVD mechanism cover.

Remove the two screws I and the one screw J attaching the DVD mechanism cover.

Remove the two screws K attaching the DVD mechanism assembly.

Remove the DVD mechanism assembly upward while pulling it backward.

DVD mechanism assembly

DVD mechanism cover

Spacer

Fig.22

Removing the power board

(See Fig.24 and 25)

Prior to performing the following procedure, remove the top cover, the rear cover, the front panel assembly, the DVD servo control board case and the digital I / O board.

Disconnect the harness from the spacer on the upper side of the DVD mechanism cover.

Remove the two screws E attaching the power board on the back of the body.

Disconnect the harness from connector CN911 and CN912 on the power board.

Remove the four screws L attaching the power board.

Disconnect connector CN913 and CN914 of the power board from the main board by pulling out them respectively.

Fig.23

Rear panel

Fig.24

Power transformer assembly

CN911,CN912

1-10

Power board

CN914

CN913

Spacer

Fig.25

TH-A10

Removing the power transformer assembly

(See Fig.24 and 25)

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

Disconnect the harnesses from connector CN911 and CN912 on the power board.

Remove the two screws M attaching the power transformer assembly.

Remove the screw E attaching the power transformer assembly on the back of the body.

Removing the main board (See Fig.26)

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

Remove the four DVD spacers on the upper side of the main board.

Remove the five screws N attaching the main board.

Power board

Rear panel

Fig.24

CN911,CN912

Fig.25

CN914

CN913

Spacer

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

Removing the power switch board

(See Fig.27)

Dithe harness from connector CN705 on the power switch board.sconnect

Remove the three screws O attaching the power switch board.

Mainboard

IC board

Fig.26

CN706

Power switch board

Fig.27

LED board

1-11

TH-A10

Removing the eject board (See Fig.28)

Disconnect the harness from connector CN702 on the eject board.

Eject board

Switch board

Remove the three screws P attaching the eject board.

Removing the LCD board (See Fig.29)

Remove the four screws Q attaching the LCD board.

Unsolder WA701, WA703 and WA704 on the LCD board.

Removing the IC board (See Fig.27)

Remove the screw R attaching the IC board.

Disconnect the harness from connector CN706 on the IC board.

Removing the LED board (See Fig.27)

CN702

WA701

Fig.28

LCD board

Fig.29

WA704

WA703

Prior to performing the following procedure, remove the LCD board and the IC board.

Disconnect the harness from connector CN705 on the power switch board.

Remove the two screws S attaching the LED board.

Removing the switch board (See Fig.28)

Prior to performing the following procedure, remove the LCD board.

Disconnect the harness from connector CN702 on the eject board.

Remove the two screws T attaching the switch board.

IC board

Fig.27

CN706

Power switch board

LED board

1-12

TH-A10

Removing the clamper base (refer to Figure 1) o Remove the top cover. o Remove the DVD mechanism unit.

1. Remove the two screws at A fixing the clamper base.

Removing the loading tray (refer to Figures 2 - 4) o Remove the clamper base.

1. Turn the up-down cam lever clockwise (in the direction of the arrow in Figure 2) to lower the position of the mechanism.

2. Manually set the loading tray to the fully-open position.

3. Stretch the tray stoppers on both sides of the loading base outward and pull out the tray.

Loading tray

Clamper base

Figure 1

Loading tray (front side)

Tray stopper

Loading tray

Loading base

Up-down cam

Lever

Figure 2

Loading tray

Push

Tray stopper

Figure 4

Figure 3

1-13

TH-A10

Removing the traverse mechanism unit (refer to Figure 5) o Remove the loading tray.

1. Remove the three screws at B fixing the traverse mechanism unit.

Traverse mechanism unit

Protecting the optical pickup o Solder the flexible ground point on the optical pickup when replacing the pickup or before detaching the mechanism control board. When assembling the unit, remove the solder last.

Removing the mechanism control board (refer to Figures 6 - 7)

o Remove the traverse unit. (Can be detached without detaching the T-mechanism unit.)

1. Remove the two screws at C fixing the mechanism control base from the bottom of the traverse unit.

2. Pull out the CN12 connector and detach the mechanism control board.

3. Remove the card wire from the CN13 connector on the mechanism control board.

4. Pull out the FPC holder from the CN12 connector on the reverse side of the mechanism control board and remove the flexible harness, referring to Figure 7.

Enlargement

Figure 5

Traverse mechanism unit

CN12

CN13

Connection area

(Solder the flexible ground point)

Flexible harness

Enlargement

FPC holder

Figure 7

Mechanism control board

Figure 6

Flexible harness

CN12

Mechanism control board

1-14

TH-A10

Removeing the turntable and spindle motor assemby (refer to Figures 8 - 9)

o Remove the traverse mechanism unit. o Solder the flexible ground point on the optical pickup. (Figure 6)

o Remove the mechanism control board.

1. Remove the flexible harness from the feed motor connector on the spindle motor board assembly.

2. Remove the three screws at D fixing the spindle motor from the bottom of the traverse chassis.

Removing the feed motor unit (refer to Figure 9) o Remove the traverse mechanism unit. o Remove the mechanism control board.

1. Remove the FPC from the feed motor connector on the turntable spindle motor board.

2. Remove the two screws at E fixing the feed motor unit.

Removing the optical pickup unit (refer to Figure 9) o Remove the traverse mechanism unit.

Guide shaft B

o Remove the mechanism control board. o Remove the feed motor unit.

1. Remove the screw at F fixing the guide shaft holder at B, then simultaneously remove the guide shaft at B and the

optical pickup unit. While doing so, slide the unit horizontally away from the guide shaft at A.

Traverse chassis

Figure 8

Traverse mechanism unit

Pick-up assembly

Guide shaft A

Feed motor assembly

Flexible harness

Feed motor connector

Turn table spindle motor unit

Figure 9

1-15

TH-A10

Removeing the loading mechanism parts (refer to Figures 10 - 11)

o Remove the clamper base. o Remove the disk tray.

1. Turn the lever counterclockwise until it stops (position 1),

while pushing the switch lever in the direction of the arrow and pushing up the pawl at A using a screwdriver.

2. Stretch the two pawls at B outward using a screwdriver

and remove the chassis.

3. Turn the lever clockwise (position 2) to remove the

up-down cam.

4. Remove the pulley gear and the pulley gear belt after

removing the screw at G fixing the pulley gear.

5. Pull out drive gear 2 then drive gear 1.

(1)When detaching

Removing the loading motor board

the chassis.

(refer to Figures 11 - 12) o Remove the clamper base. o Remove the disk tray.

1. Remove the loading belt.

2. Remove the two screws at H fixing the loading motor.

3. Remove the screw at I and the three pawls at C fixing

the loading motor base from the reverse side of the loading base.

Up-down cam

Pawl B

chassis.

Lever

Up-down cam

Figure 10

Loading base

Pawl A

Chassis

Pawl B

Switch lever

(2)When detaching the up-down cam.

Up-down cam

Switch lever

Loading motor unit

Loading base

Loading belt

Loading base

Drive gear 1

Drive gear 2

Pulley gear

Figure 11

Loading motor board

Pawl C

1-16

Figure 12

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