JVC UXA-52-R Service manual

SERVICE MANUAL

MICRO COMPONENET SYSTEM

UX-A52R

- RDS -

COLOR

DIMMER

CONTROL

STANDBY/ON

CLOCK

SLEEP

FM MODE

/TIMER

1 2 3

DISPLAY

4 5 6

DISPLAY

TA/NEWS

PTY

/INFO

7 8 9

SELECT–+

SET

CANCEL

REPEAT

PLAY MODE

REV.MODE

FM/AM

TAPE

AUX/MD

BEEP

SOUND

AHB

VOLUME

MODE

PRO

RM-SUXA52R

Contents

Safety precautions Preventing static electricity Important for laser products Disassembly method Adjustment Method

PHONES

1-2 1-4 1-5 1-6 1-25

MICRO COMPONENT SYSTEM UX-A52R

COMPACT

DIGITAL AUDIO

STANDBY/ON

B ---------------------------- U.K. E -------- Continental Europe EN ----------- Nor them Europe

Flow of functional operation until TOC read (CD) Maintenance of laser pickup Replacement of laser pickup Description of major ICs

Area Suffix

1-29 1-30 1-30 1-31~49

No.21064

Feb. 2002

1-1

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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 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.

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.

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

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(U.K only)

2. Any unauthorised design alterations or additions will void the manufacturer's guarantee ; furthermore the manufacturer cannot accept responsibility for personal injury or property damage resulting therefrom.

3. Essential safety critical components are identified by ( ) on the Parts List and by shading on the schematics, and must never be replaced by parts other than those listed in the manual. Please note

however that many electrical and mechanical parts in the product have special safety related characteristics. These characteristics are often not evident from visual inspection. Parts other than specified by the manufacturer may not have the same safety characteristics as the recommended replacement parts shown in the Parts List of the Service Manual and may create shock, fire, or other hazards.

1. Service should be performed by qualified personnel only.

2. This equipment has been designed and manufactured to meet international safety standards.

3. It is the legal responsibility of the repairer to ensure that these safety standards are maintained.

4. Repairs must be made in accordance with the relevant safety standards.

5. It is essential that safety critical components are replaced by approved parts.

6. 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.

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Preventing static electricity

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.

Shorting round

1.Solder is put up before the card wire is removed from connector on the CD substrate as shown in Figure. (When the wire is removed without putting up solder, the CD pick-up assembly might destroy.)

2.Please remove solder after connecting the card wire with when you install picking up in the substrate.

1-4

Flexible wire

Shorting round

CN601 on mechanism board

Important for laser products

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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 laserradiation and is equipped with safety switches whichprevent 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.

VARNING : Osynlig laserstrålning är denna del är öppnad

och spårren är urkopplad. Betrakta ej strålen.

VARO : Avattaessa ja suojalukitus ohitettaessa olet

alttiina näkymättömälle lasersäteilylle.Älä katso säteeseen.

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.

CAUTION

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

ADVARSEL : Usynlig laserstråling ved åbning , når

sikkerhedsafbrydere er ude af funktion. Undgå udsættelse for stråling.

ADVARSEL : Usynlig laserstråling ved åpning,når

sikkerhetsbryteren er avslott. unngå utsettelse for stråling.

REPRODUCTION AND POSITION OF LABELS

WARNING LABEL

CLASS 1 LASER PRODUCT

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Disassembly method

Removing the rear cover

(See Fig.1 and 2)

Remove the eight screws A on the back of the body.

Remove the two screws B on the bottom of the body.

Unlock the speaker terminal and the antenna terminal, then remove the rear cover backward with releasing the hooks.

Removing the side panels

(See Fig.3 to 5)

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

Rear cover

Antenna terminal

Side panel (R)

Speaker terminal

Fig.1

(Bottom)

Rear cover

Remove the two screws C attaching the side panels on the bottom of the body.

Remove each side panel backward while releasing the eight joints a as shown in Fig.4 and 5.

Joint a

Side panel (L)

Fig.2

Side panel (R)

Side panel (L)

Fig.3

Joint a

1-6

Side panel (R)

Fig.4

Side panel (L)

Fig.5

Removing the top panel (See Fig.6 and 7)

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

Remove the two screws D on each side of the body.

Release the two joints b on each side of the body and remove the top panel in the direction of the arrow.

Disconnect the card wires from connector CN705 on the system control board on the left side of the body.

Joint b

Top panel

Fig.6

CN705

Joint b

Removing the cassette mechanism assembly section (See Fig.8)

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

Disconnect each wire from connector CN706, CN715 and CN716 on the system control board on top of the body.

Remove the four screws E retaining the cassette mechanism assembly section on top of the body.

REFERENCE:

Reference: If necessary, remove the spacer marked h and the wire from the Cassette mechanism assembly section.

h (spacer)

System control board

Fig.7

E E

CN715

Cassette mechanism section

Fig.8

System control board

CN706

CN716

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Removing the system control board

(See Fig.9)

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

Disconnect the card wire from connector CN701 and the wire from connector CN706, CN715, CN716 on the system control board.

Remove the screw F on the left side of the body.

Disconnect connector CN709, CN711 and CN712 on the system control board from the body outward.

Disconnect the card wire from connector CN704 on the underside of the system control board.

Removing the tuner board (See Fig.10)

Prior to performing the following procedure, remove the rear cover and the right side panel.

CN706

CN716

CN712

CN704

CN715

CN701

CN711

CN709

System control board

Fig.9

Tuner board

Disconnect the card wire from connector CN1 on the tuner board on the right side of the body.

Remove the screw G and remove the tuner board upward while disengaging the three joints c.

CN1

Joints c

Fig.10

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Removing the front panel assembly

(See Fig.11 and 12)

Prior to performing the following procedure, remove the rear cover, the side panels, the top panel and the system control board.

Release the two joints d on the lower right and left sides of the front panel assembly, then remove the front panel assembly toward the front.

Front panel assembly

Fig.11

Joint d

Removing the headphone jack board

(See Fig.13 and 14)

Prior to performing the following procedure, remove the rear cover, the side panels, the top panel, the system control board and the front panel assembly section.

Disconnect the wire from connector CN804 on the main board.

Remove the plastic rivet fixing the headphone jack board.

Joint d

Fig.12

Main board

CN804

Headphone jack board

Fig.13

Plastic rivet

Headphone jack board

Fig.14

1-9

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Removing the main board / the heat sink

(See Fig.15 to 17)

Prior to performing the following procedure, remove the rear cover, the side panels, the top panel, the cassette mechanism assembly section and and the system control board.

Disconnect the wire from connector CN804 on the main board.

Remove the five screws H attaching the cassette mechanism bracket.

Remove the screw G attaching the grounding terminal extending from the main board.

Disconnect connector CN805 on the main board from the AC jack board while pulling out it. Remove the main board in the direction of the arrow and disconnect the wire from connector CN803 on the reverse side of the main board.

Remove the three screws I attaching the heat sink on the reverse side of the main board.

Main board

CN804

Cassette mechanism bracket

Fig.15

Main board

CN804

CN805

CN803

Heat sink

Tuner board

Fig.16

Fig.17

Main board

1-10

Removing the AC jack board

(See Fig.18 and 19)

Prior to performing the following procedure, remove the rear cover, the side panels, the top panel, the cassette mechanism assembly section, the system control board and the main board / the tuner board.

Disconnect the wire from connector CN809 on the AC jack board.

Remove the screw J and screw K attaching the AC jack board.

Power transformer assembly

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AC jack board

CN809

Fig.18

CN809

Removing the power transformer assembly (See Fig.20)

Prior to performing the following procedure, remove the rear cover, the side panels, the top panel, the cassette mechanism assembly section, the system control board and the main board.

Disconnect the wire from connector CN809 on the AC jack board.

Cut off the band setting the wire on the CD mechanism cover.

Power transformer assembly

Fig.19

AC jack board

CN809

Band

Remove the four screws L attaching the power transformer assembly.

Fig.20

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Removing the CD mechanism assembly

(See Fig.21 to 23)

Prior to performing the following procedure, remove the rear cover, the side panels, the top panel, the cassette mechanism assembly section, the system control board, the front panel assembly section, the main board / the tuner board and the AC jack board.

Cut off the band setting the wire on the CD mechanism cover.

Release the wire extending from the headphone jack board from the spacer and the three notches of the CD mechanism cover on the left side of the body.

Remove the four screws M on the left and right side of the CD mechanism cover. Then remove the CD mechanism cover upward.

Remove the three screws N attaching the CD mechanism assembly.

CD mechanism cover

Band

Notches

CD mechanism assembly

Spacer

Notch

Fig.21

CD mechanism cover

Band

Fig.22

CD mechanism assembly

Fig.23

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Prior to performing the following procedure, remove the rear cover, the side panels, the top panel, the system control board and the front panel assembly section.

Removing the relay board (See Fig. 24)

Disconnect the wire from connector CN906, CN907

1. and the card wire from CN908 on the relay board respectively.

Remove the two screws O.

Removing the drive motor assembly

(See Fig.25)

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

CN907

Drive motor assembly

CN908

Fig.24

Door switch board

Relay board

CN906

Remove the four screws P attaching the drive motor assembly.

Removing the belt and the drive motor

(See Fig.26)

REFERENCE:

Remove the two screws Q attaching the plate.

Remove the belt from the two pulleys.

Remove the two screws R attaching the drive motor.

REFERENCE:

The belt and the drive motor can be removed respectively without removing the drive motor assembly from the front panel section.

When removing the drive motor only, remove the belt from the drive motor pulleys in advance.

Fig.25

Belt

Plate

Drive motor

Fig.26

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Removing the door switch board

(See Fig.27 and 28)

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

Loosen the screw S attaching the door switch.

Remove the door switch board while releasing it from the joint e.

CAUTION:

When reattaching the door switch board, fit it to the joint e and check the operating state of the switch before tightening the screw S.

Removing the LCD section

(See Fig.29 to 31)

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

Drive motor assembly

Switch section

Fig.27

Door switch board

Fig.28

Door switch board

Joint e

Loosen the two screws T attaching the lock lever.

Push the part f of the lock lever in the direction of the arrow as shown in Fig.30-1 / 30-2 and disengage the LCD section from the front panel assembly.

CAUTION:

Because the LCD may come off, hold it when loosening the screws T.

Lock lever f Lock lever f

Lock lever

LCD section

Lock lever

Front panel assembly

Fig.29

Front panel assembly

Joint f

1-14

Fig.30-1 Fig.30-2

Joint f

Fig.31

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Removing the LCD board assembly

(See Fig.32 to 36)

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

Remove the four screws U attaching the case cover.

Remove the four screws V attaching the LCD panel on the back of the LCD section.

Remove the LCD cover.

Release the three joints g and remove the LCD board assembly in the direction of the arrow.

Case cover

Fig.32

LCD section

Joint g

Fig.33

LCD panel

Fig.34

Joint g

LCD cover

LCD board assembly

Fig.35 Fig.36

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

Removing the operation switch board

(See Fig.37)

Remove the seven screws W attaching the operation switch board on the reverse side of the top panel.

Cassette amplifier board

Fig.37

Operation switch board

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Removing the CL. Base Assembly and Tray (Refer to Figs. 1 to 5.)

1. Remove the two screws A fastening the CL. base assembly from the top of the CD mechanism assembly.

2. Move the CL. base assembly diagonally upwards as indicated by the arrow to release it from the two hooks a.

3. Turn the idle gear in the arrow-marked direction from the upper side of the CD mechanism assembly. Accordingly, the TRAMECHA assembly moves downwards.

Note: When drawing out the tray, shift down the

TRAMECHA assembly to the position where the tray does not contact the T-T assembly of the TRAMECHA assembly.

4. Draw out the tray frontwards for removing it.

CL. base assembly

TRAMECHA assembly

Hook a

Fig. 1

Hook a

Idle gear

Note: When reinstalling the tray: Turn the idle gear so that the part b of the

tray gear is positioned in the part c shown in Fig. 4. (Eject position)

Engage the right and left hooks d and e of

the tray with the right and left grooves of the TRAMECHA assembly respectively for retaining the tray.

Idle gear

Tray gear

Tray

Fig. 2

TRAMECHA assembly

Idle gear

Tray

Fig. 3

Hook d

Tray

Tray gear

Part c

Part b

Fig. 4Fig. 5

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Removing the TRAMECHA Assembly

(Refer to Figs. 6 to 9.)

Remove the CL. base assembly and tray.

Reference: The TRAMECHA assembly can be

removed without removal of the mechanism board.

1. If the TRAMECHA assembly is lowered and it is located out of the PLAY position, turn the idle gear in the arrow-marked direction so that the hole in the part f of the tray gear meets the hole on the CL. base assembly. (Set the TRAMECHA assembly at the PLAY position.)

2. Remove the three screws B fastening the TRAMECHA assembly and then remove the TRAMECHA assembly upwards from the front side.

3. At the same time, remove the spring from the groove of the CH. base assembly in the part g of the TRAMECHA assembly.

Note: When reinstalling the TRAMECHA assembly:

Check to see if the spring is properly engaged with groove of the CH. base assembly in the part g of the TRAMECHA assembly. After making sure that the three insulators of the TRAMECHA assembly are properly set on the bosses of the L. base assembly's guide, fasten them with the screws.

TRAMECHA assembly

Part g

L. base assembly

Fig. 6

Fig. 7

Idle gear

Tray gear

Part f

1-18

Spring

Part g

Fig. 8

Spring

Groove of CH. base assembly

Fig. 9

Removing the Mechanism Board

(Refer to Fig 10.)

Reference:The mechanism board can be removed

without removal of the TRAMECHA assembly.

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Flexible wire

Shorting round

Note: Before disconnecting the flexible wire coming

from the pickup from the connector, be sure to solder its shorting round. If the flexible wire is connected without soldering, it may cause breakdown of the pickup.

1. Solder the shorting round of the flexible wire connected with the mechanism board from the back of the mechanism assembly.

2. Disconnect the flexible wire from the connector CN601 on the mechanism board.

3. Remove the three screws C fastening the mechanism board.

4. Unsolder the two points of the part h and one point of the part i of the mechanism board. Then, remove the mechanism board upwards.

Note: When reinstalling the mechanism board,

connect the flexible wire coming from the pickup to the connector first and then remove the solder from the shorting round of the flexible cable.

Soldered part h

CN601 on mechanism board

Soldered part i

Fig. 10

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Removing the Pickup (Refer to Figs. 11 to 14.)

Remove the CL. base assembly and tray. Remove the TRAMECHA assembly.

Reference: The pickup can be removed without

removal of the mechanism board.

Note: Before disconnecting the flexible wire coming

from the pickup from the connector, be sure to solder its shorting round. If the flexible wire is connected without soldering, it may cause breakdown of the pickup.

1. Solder the shorting round of the flexible wire connected with the mechanism board from the back of the TRAMECHA assembly.

2. Disconnect the flexible wire from the connector CN601 on the mechanism board.

Part j of rack plate

CH. base assembly

Flexible wire

Shorting round

CN601 on mechanism board

Fig. 11

T-T assembly

Pickup assembly

3. Turn the idle gear in the arrow-marked direction from the top of the TRAMECHA assembly so that the pickup assembly is shifted to the reverse side of the T-T assembly. Move the pickup assembly until the part j of the rack plate in the lower part of the pickup assembly comes out of the CH. base assembly.

4. Remove the two screws D retaining the shaft of the pickup assembly. Next, disengage the hook k from the CH. base assembly and then remove the pickup assembly together with the shaft.

5. Pull the shaft out of the pickup.

6. Remove the two screws E fastening the rack plate from the pickup.

7. Remove the screw F retaining the P.S. spring from the pickup.

Idle gear

Shaft

Fig. 12

Pickup assembly

Part k

CH. base assembly

Fig. 13

Pickup

1-20

Part j

Rack plate

P.S. spring

Fig. 14

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Reinstalling the Pickup Assembly

(Refer to Figs. 15 and 16.)

Reference: Refer to the explanation of "Removing

the Pickup" on the preceding page.

1. Fit the P.S. spring and rack plate to the pickup.

2. Insert the shaft into the pickup.

3. Engage the hook k of the pickup assembly with the CH. base assembly first, and set the part j of the rack plate in the opening I next. Then, reinstall the pickup assembly while shifting it to the T-T side (inward) so that the part m of the rack plate is positioned as shown in Fig. 16.

4. Move the pickup assembly to the center position and fasten the shaft with the two screws D. (Make sure that the part n of the rack plate is correctly engaged with the middle gear.)

5. After passing the flexible wire coming from the pickup through the opening of the CH. base assembly, connect it to the connector CN601.

Part I

Part j

Part m

Part k

Pickup assembly

CH. base assembly

Fig. 15

Middle gear

Note: When reinstalling the pickup assembly,

remove the solder from the shorting round after connecting the flexible wire coming from the pick to the connector CN601.

Removing the Feed Motor Assembly

(Refer to Fig. 17.)

Remove the CL. base assembly and tray. Remove the mechanism board.

Remove the two screws E fastening the feed motor assembly from the top of the mechanism assembly.

Rack plate

Part n

Fig. 16

Feed motor assembly

Fig. 17

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CAUTION:

Removing the side bracket (L) and (R) / load board (See Fig.1 to 4)

Remove the E-washer attaching the load arm on the right side of the body.

Turn the load arm in the direction of the arrow to release from the cassette hook at the joint a.

Remove the spring (1) attaching the trig lever.

Move the trig lever in the direction of the arrow and release it from the two holes b.

Remove the screw A attaching the load board on the right side of the body and unsolder the wire extending from the sub motor.

Prior to performing the following procedures, turn the mode gear in the direction of the arrow to move each section to the eject position.

Joint a

Slide bracket

Load arm

E-washer

Load arm

Fig.1

Hole b

Spring (1)

REFERENCE:

Remove the spring (2) and the holder collar on the right side of the body.

Remove the two screws B attaching the side bracket unit (R) in the direction of the arrow.

Remove the four screws C attaching the side bracket (L) in the direction of the arrow.

The side bracket unit (R) can be removed even if the load board is attached. In such case, make sure to unsolder the wire extending from the sub motor.

Side bracket unit (L)

Fig.2

Load board

Soldering

Fig.3

Cassette hanger assembly

1-22

Side bracket unit (R)

Spring (2)

Holder collar

Fig.4

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Removing the cassette hanger assembly / cassette holder (See Fig.5)

Prior to performing the following procedure, remove the side bracket (L) and (R).

Remove the slit washer attaching the cassette hanger assembly and pull out the pin.

Move the cassette hanger assembly in the direction of the arrow to release the boss of the joint c on the left rear side and detach the cassette hanger assembly upward.

REFERENCE:

The cassette hanger assembly is detached with the cassette holder.

Removing the pinch roller (F) and (R)

(See Fig.6 to 8)

Cassette hanger assembly

Cassette holder

E-washer

Fig.5

Prior to performing the following procedure, remove the side bracket (L), (R), cassette hanger assembly / cassette holder.

Release the tab d in the direction of the arrow and pull out the pinch roller upward.

REFERENCE:

The above method is for removing the pinch roller (F) and (R).

Pinch roller (F)

Pinch roller (R)

Fig.6

Tab d

Fig.8Fig.7

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Removing the head assembly / head board (See Fig.9 and 10)

Prior to performing the following procedure, remove the side bracket (L), (R), cassette hanger assembly / cassette holder.

Remove the spring on the lower side of the head assembly.

Remove the two screws D and remove the head assembly upward.

Remove the screw E attaching the head board. Unsolder the flexible wire extending from the head assembly if necessary.

Head board

Fig.9

Head assembly

Soldering

Removing the flywheel assembly (F) and (R) (See Fig.11 and 12)

Prior to performing the following procedure, remove the side bracket (L), (R), cassette hanger assembly / cassette holder.

Remove the belt and sub belt on the bottom of the body.

Remove the polywasher from the flywheel (F) and (R) on top of the body.

Pull out the flywheel (F) and (R).

Sub belt

Flywheel assembly (R)

Fig.10

Belt

Flywheel assembly (F)

Fig.11

1-24

Polywasher

Fig.12

Polywasher

Adjustment Method

1. Jigs and test instruments

Test disc (CTS-1000) Test tape (VT712) Test tape (VT703) Test tape (AC225)

2. Adjustment and check items

1) Indications in the modes that all LCD's are on

2) CD section

(1) Indication of the C1 error (2) Cancel of the C1 error indication

3. Adjustment and check method

1) CD section

(1) Indication of the C1 error

While pressing both the POWER key and BACK SKIP key on the main unit, turn on the primary power supply.

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FL indication

CRC = 0

Press the CD OPEN/CLOSE key and insert the test disk.

Press the CD PLAY key. The set starts counting and the number of error correction times is indicated every 10 seconds.

FL indication

CRC = ***

(2) Cancel of the C1 error indication

To cancel the C1 error indication, cut off the power supply.

200 Hz or less

1-25

UX-A52R

Cassette section

Playback/Recording & eraser head

Head azimuth adjusting screw (Forward side)

Playback/Recording & eraser head

Removing the Cassette Mechanism Assembly

1. Remove the rear cover.

2. Remove the side panels (right and left).

3. Remove the cassette mechanism assembly.

4. Remove the four screws S fastening the cassette mechanism assembly from the back of the cassette mechanism.

5. Press the EJECT button on the front side of the cassette mechanism assembly to open the cassette door, and then remove the cassette mechanism assembly.

Head azimuth adjusting screw (Reverse side)

BIAS TEST POINT

1-26

GND

PCB FMB

Check and adjustment of the Head amplifier section

UX-A52R

Item

1. Head azimuth adjustment

2. Tape speed adjustment

(Reference value) Speed difference between the normal and reverse directions

Check/Adjustment Method

1) Play back the end part of the test tape VT703 (10 kHz).

2) Adjust the head azimuth screws so that the output becomes maximum in both the normal and reverse directions. After adjustment, lock the screws with screw bond without fail. Measuring output terminal: Speaker terminal, 4 load resistance Difference between L-ch and R-ch: Within 3 dB Difference between FWD and REV directions: Within 4 dB

Adjust max level in FWD and REV. After adjusting, should be Applied bond (THREEBOND 1401 A/C) to screw.

Azimuth screw

Screw for REV

Neji Lock

1) Play back the end part of the test tape VT712 (3 kHz).

2) Adjust VR37 so that the frequency counter reads 3000 15 Hz in playback in the normal direction.

Measuring output terminal: Speaker terminal Make sure that speed difference between the normal and reverse directions is 60 Hz or less by reading of the frequency counter. (With the beginning part of the test tape)

Azimuth for FWD

Neji Lock

Adjusting Point

Head azimuth screw

phase

(0 ) (45 )

VR37

Standard Value

Maximum output

3000 15Hz

60 Hz or less

Wow and flutter

3. Recording / playback frequency characteristic adjustment

(Reference value) Recording bias frequency

(Reference value) Erasing current

Play back the end part of the test tape VT712 (3 kHz). Make sure that the wow and flutter meter reads 0.25 % (WRMS) or less.

1) Set a blank cassette tape (Type I: AC225) and enter the set into the recording pause mode.

2) Cancel the pause mode and start recording. Repeat to input the 1 kHz and 10 kHz reference signals alternately from the CD test disk to record the signals on the blank tape.

3) While playing back the repeatedly input 1 kHz and 10 kHz reference signals, adjust VR31 so that output level of 10 kHz signals is +2 dB 1 dB of 1 kHz.

1) Set a blank cassette tape (Type I: AC225) and enter the set into the recording pause mode.

2) Make sure that the bias frequency at the bias test point (Refer on 1-26 board drowing) on the head amplifier board is 70 9 kHz.

1) Set a blank cassette tape (Type I: AC225) and enter the set into the recording pause mode.

2) After connecting a 1 resistor to the erasing head in series, cancel the pause mode and start recording. Connect the electronic voltmeter to both the terminals and measure the erasing current.

0.25 % (WRMS) or less

VR31

-1dB 1dB

70 9kHz

Erasing current: 60 mA (Type I tape)

1-27

UX-A52R

Extension code connecting method

Cassette mechanism assembly

System control board

(CN706, CN715, CN716)

QUQ110-1940BJ

CD mechanism assembly

CD servo control board

(CN651)

Extension wire

System control board

(CN704)

1-28

Flow of functional operation until TOC read (CD)

Power ON

Power Key

Slider turns REST SW ON.

Automatic tuning of TE offset

Check to see if the voltage at the pin 72 of IC701 or pin 5 of CN602 becomes 0 V for an instant. (The moment the switch is turned on, the voltage becomes 0 V.)

UX-A52R

Check Point

VREF

Tracking error waveform at TOC reading

pin 25 of IC601(TE)

Approx

1.8V

Tracking servo

Disc statas to rotate

off statas

Automatic measurement of TE amplitude and automatic tuning of TE balance

Approx.3sec

Tracking servo on statas

Disc to be braked to stop

TOC reading finishes

500mv/div 2ms/div

Fig.1

Laser ON

Detection of disc

Automatic tuning of Foucus offset

Automatic measurement of Focus A-curve amplitude

Disc is rotated

Focus servo ON (Tracking servo ON)

Automatic measurement of Tracking error amplitude

Automatic tuning of Tracking error balance

Make sure of the H level at the pin 40 of IC603.

Confirm that the Focus error S-curve siganl at the pin28 of IC603 is approx.2Vp-p

Confirm that the siganl from pin24 IC603 (R645) is 0V as a accelerated pulse during approx.400ms.

Make sure that the TE signal (1.8 Vp-p approx.) indicating the tracking servo off status is output from the pin 25 (one side of R609) of IC601.

Automatic tuning of Focus error balance

Automatic tuning of Focus error gain

Automatic tuning of Tracking error gain

TOC reading

Play a disc

Confirm the eys-pattern at the lead of TP602

1-29

UX-A52R

Maintenance of laser pickup

(1) Cleaning the pick up lens Befor you replace the pick up, please try to clean the lens with a alcohol soaked cotton swab.

(2) Life of the laser diode (Fig.1) When the life of the laser diode has expired, the following symptoms wil appear. (1) The level of RF output (EFM output:ampli tude of eye pattern) will below.

Is RF output

1.25 0.22Vp-p?

YES

O.K

Replace it.

Replacement of laser pickup

Turn off the power switch and,disconnect the power cord from the ac outlet.

Replace the pickup with a normal one.(Refer to "Pickup Removal" on the previous page)

Plug the power cord in,and turn the power on. At this time,check that the laser emits for about 3seconds and the objective lens moves up and down. Note: Do not observe the laser beam directly.

Play a disc.

(Fig.1)

(3) Semi-fixed resistor on the APC PC board The semi-fixed resistor on the APC printed circuit board which is attached to the pickup is used to adjust the laser power.Since this adjustment should be performed to match the characteristics of the whole optical block, do not touch the semi-fixed resistor. If the laser power is lower than the specified value,the laser diode is almost worn out, and the laser pickup should be replaced. If the semi-fixed resistor is adjusted while the pickup is functioning normally,the laser pickup may be damaged due to excessive current.

Check the eye-pattern at TP602.

Finish.

1-30

+ 97 hidden pages

JVC UXA-52-R Service manual

Specifications and Main Features

Frequently Asked Questions

User Manual