Jvc XM-PX70-WT Service Manual

XM-PX70WT/BU/PN

SERVICE MANUAL

PORTABLE MINIDISC PLAYER

XM-PX70WT/BU/PN

UB Hong Kong

Area Suffix

Contents

Safety Precautions Attention when

MD pick up is exchanged

Disassembly method

Adjustment method

Maintenance of laser pickup Replacement of laser pickup Description of major ICs Attention when parts are exchanged

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1-3 1-4 1-9 1-10 1-10 1-11

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No.20897

Jan. 2001

XM-PX70WT/BU/PN

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.

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

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.).

0.15 F AC TYPE

1500 10W

Place this probe on each exposed metal part.

This corresponds to 0.5 mA AC (r.m.s.).

Good earth ground

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.

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XM-PX70WT/BU/PN

Attention when MD pickup is exchanged

1. About the static electricity protection measures

The laser diode in the traverse unit (optical pick up) is easy to be destroyed by clothes and the human body to the electrified static electricity. Please note the explosion by static electricity when repairing.

2. About the earth processing for the electrostatic destruction prevention

In the equipment which uses an optical pick up (laser diode), an optical pick up is destroyed by the static electricity of the work environment. Please do the earth processing and work.

1) Earth of work stand Please pull the conductive material (conductive sheet) or the iron plate to the depository place of the traverse unit (optical pick up), and take the earth to ground.

2) Human body earth Please use the anti-static wrist strap to exhaust the electrified static electricity to the human body.

anti-static wrist strap

Conductive material (conductive sheet) or the iron plate

3. Handling the optical pick up

1) Please return according to a correct procedure based on short processing after exchanging parts.

2) Do not use a tester to check the condition of the laser diode in the optical pick up .The tester 's internal power source can easily destroy the laser diode.

4. Attention when unit is disassembled

Please refer to "Disassembling method" for how to detach .

1) Please be sure to solder before a flexible wire is removed from connector on a main printed circuit board as shown. if you removes without soldering.the MD picking up assembly might destroy

2) When installing , solder in the part of short round should be removed after a flexible wire is connected with connector.

Solder short

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XM-PX70WT/BU/PN

Disassembly method

Removing the MD door assembly

(See Fig.1 and 2)

1.

Shift the door lever to open the door.

2.

Remove the four screws A and detach the MD

assembly from the main body.

Removing the holder assembly

(See Fig.3 and 4)

Prior to performing the following procedure, remove the MD door assembly.

1.

Turn the holder assembly as shown in Fig.3.

2.

Pull the side arm (L) marked a and

Open the holder assembly as

Move the marked b in the direction of the arrow and

3. release it from the shaft.

shown in Fig.4.

remove outward.

door

MD door assembly

A

Door lever

Holder assembly

Door lever

Fig.1

MD door assembly

A

Fig.2

Move the part c inward and pull out the holder

4. assembly from the shaft.

ATTENTION:

“U-shaped” notch

When reassembling, first reattach the part c to the shaft of the chassis assembly. And next, fit the “U-shaped” notch to the shaft.

Holder assembly

Part b

Part a

Side arm (L)

Fig.3

Holder assembly

Part c shaft

1-4

Part c

Fig.4

XM-PX70WT/BU/PN

Removing the chassis assembly

(See Fig.5 to 7)

Prior to performing the following procedure, remove the MD door assembly and the holder assembly.

Open the battery lid. Release the tab d and pull out

1. the battery lid.

Remove the screw B and pull out the side arm (R)

2. upward.

Remove the two screws C and pull out the eject unit.

3.

Remove the screw D, E, F, G and H attaching the

4. chassis assembly respectively.

Disengage the three joints e of the bottom case and

5. the battery holder. Remove the chassis assembly and the jack cover at once.

Tab d

Battery lid

Chassis assembly

Side arm (R)

Joint e

D

B

Joint e

Fig.5

Eject unit

C

Chassis assembly

Joint e

Bottom case

E

F

Battery holder

Fig.6

Chassis assembly

H

G

Fig.7

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XM-PX70WT/BU/PN

Removing the main board and the battery holder (See Fig.8 and 9)

Prior to performing the following procedures, remove the MD door assembly, the holder assembly and the chassis assembly.

ATTENTION:

Solder the short circuit round of the flexible wire on

1. the main board.

Disconnect the flexible wires from connector CN301

2. and CN401 on the main board.

Remove the one screw I attaching the main board.

3. Remove the main board with the battery holder .

Unsolder the four soldered parts f retaining the main

4. board and the battery holder.

Before disconnecting the flexible wire extending from the pickup, make sure to solder the short circuit round to prevent damage to the pickup.

CN401

CN301

Short circuit round

Headphone jack assembly

Short circuit round

Battery holder

Soldering f

I

Soldering f

Main board

Fig.8

CN401

ATTENTION:

When reassembling, connect the flexible wire extending from the pickup to the connector on the main board and unsolder the short circuit round.

Removing the headphone jack assembly

(See Fig.10)

Prior to performing the following procedures, remove the MD door assembly, the holder assembly, chassis assembly and the main board.

Disconnect the flexible wire extending from the

1. headphone jack from connector CN601 on the main board.

CN301

Fig.9

Battery holder

CN601

1-6

Headphone jack assembly

Main board

Fig.10

XM-PX70WT/BU/PN

<Removal of the MD

mechanism section>

Prior to performing the following procedures, remove the MD door assembly, the holder assembly, the chassis assembly and the main board.

Removing the spindle motor

(See Fig.11)

Unsolder the part g on the flexible wire extending

1. from the underside of the chassis assembly to the spindle motor.

ATTENTION:

Remove the three screws J attaching the spindle

2. motor.

Removing the pickup unit (See Fig.11)

Do not spill flux on the gear and others.

Lead screw

Part i

Pickup unit

Part h

Spindle motor

Lead screw

Chassis assembly

Worm gear

Slit washer

K

Shaft holder

Part g

J

Fig.11

L

ATTENTION:

Remove the slit washer and the worm gear from the

1. underside of the chassis assembly.

Remove the screw K attaching the shaft holder and

2. draw out the shaft (lead screw).

Pull out the pickup unit and the lead screw while

3. disengaging the part h and i.

When handling the pickup unit, touch the parts marked in Fig.13 only.

Removing the pickup (See Fig.12 and 13)

ATTENTION:

When handling the pickup unit, touch the parts marked in Fig.13 only.

Lead spring

Pickup

Fig.12

Touch these parts only.

Remove the screw L and the lead spring.

1.

Pull out the shaft from the pickup.

2.

Fig.13

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XM-PX70WT/BU/PN

Removing the feed motor (See Fig.14)

Peel off the adhesive tape j on the flexible wire on

1. the underside of the feed motor.

Unsolder soldering k connecting the flexible wire to

2. the feed motor.

Remove the two screws M attaching the feed motor.

3.

ATTENTION:

When reassembling, reattach the flexible wire with an adhesive tape and solder.

j

Feed motor

Chassis assembly

M

Soldering k

M

Pickup unit

Fig.14

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XM-PX70WT/BU/PN

Adjustment method

This model is auto adjustment by Remote Controller. Please adjust the attached remote controller.

Equipments----- 1. Remote controller 2. DC power supply

3. Laser power meter 4. MO disc (AU-1)

5. Pre master disc (TGYS 1) <Test mode setting method>

Press < PLAY MODE + DISPLAY + BASS > and < PLAY >key together more than 3sec. at power off condition. < VOL > next item .< VOL+ >before item.

LCD indication

0. TMD-V2

Test mode setting OK. Indicate at 2sec. When LCD indicate [NG] at another item, Return back this item by press (STOP) key

Resume initialize LCD Indication change :

* Initializing

*

Servo initialize LCD Indication change : [ ]

PLAY LASER Insert the laser power meter. Executes by < BASS > LCD Indication change :[XX:YY]

Up by < VOL+> .Down by <VOL > LCD Indication change :[VW.YY]

Setting by <STOP> LCD Indication change :[ OK ]

Laser power adjust 560 adjust

Adjust power-supply voltage 1.5v 20mv before the laser power is adjusted and stops.

Resume

Initializing

Servo

PLAY LASER

5. M o T G

7.

FEED Executes by < BASS >

<VOL+> :Pickup is go to outside

Press < STOP >

MO TG Insert the Recordable disc. Executes by < BASS > LCD Indication change : [ ]

MO DISC ADJUST Executes by < BASS > LCD Indication change : [ ]

*

Press < STOP >

LCD Indication change : [OK

Pre TG Insert the Pre master disc.

Executes by < BASS >

LCD Indication change : [ ]

Pre DISC ADJUST Executes by < BASS >

LCD Indication change : [

Press < STOP > RESET

Executes by < BASS >

LCD Indication :

*

Left out the test mode ,power off ,and END.

LCD Indication change :[FwdBwd]

< VOL-> :Pickup is go to inside

LCD Indication change :[OK ]

*

Adjusting

]

*

Adjusting

MO DISC ADJUST

XXYYZZ

FEED

]

1-9

XM-PX70WT/BU/PN

Maintenance of laser pickup

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

(2) Life of the laser diode When the life of the laser diode has expired, the following symptoms will appear.

1. The level of RF output (EFM output:ampli tude of eye pattern) will below.

Is the level of

RFOUT under

0.35Vp-p?

YES

O.K

NO

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.

Check the eye-pattern at TP1.

Finish.

(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.

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Description of major ICs

JCV8002-W (IC601) : Head phone amp

1. Pin layout 24 ~ 19

1

XM-PX70WT/BU/PN

18

2. Block diagram

3. Pin function

Symbol

no.

CC2

V

1

OUT

2 PWR GND

3

OUT

4

DET

5

AGC IN

6

BST OUT

7

BST NF

8

LPF

9

BST NF

10

ADD IN

11

V

12

ref

V IN

13

ref

GND

14

BEEP IN

15

BST SW

16

MT SW

17

PW SW

18

MT TC

19

V

20

CC1 CC

IN

21

IN

22 23

BEEP OUT

24

BEEP OUT

V Power amplifier output

A

GND in power amplifier output steps Power amplifier output

B

Smoothness of level detection of boost BST amplifier input signal level variable control by input lever to boost AGC input terminal Output terminal of BST amplifier2

2

Terminal NF of BST amplifier2 Output BST amplifier1

2

NF of BST amplifier1

1

ADD amplifier input Standard potential circuit Standard potential circuit Power part input steps GND Beep input terminal Beep output terminal Mute switch Power On/OFF switch Mute smoothing Power mute switch Main parts V Power amplifier input

B

Power amplifier input

A

Beep output terminal

B

Beep output terminal

A

~

6

7 ~ 12

PW

SW MT TC

PW

19

SW

V

CC1

20

IN

B

21

IN

A

22

BEEP OUT

B

23

BEEP OUT

A

24

V

CC2

1

FUNCTION

(+B) in power amplifier output steps

CC2

CUT

MT SW

~

13

BST2

BST AGC

Vref IN

AGC IN

13

Vref

6

Vref

ADD IN

BST OUT

12

11

10

BST NF1

9

LPF

2

8

BST NF

2

7

161718

BST SW

PWR GND

BST SW

3

MT SW

PW A

A

2

BEEP IN

PW B

OUT

15

BEEP

B

4

GND

DET

14

BST1

5

AGC

1-11

XM-PX70WT/BU/PN

CXA2588R (IC300) : RF amp.

1. Pin layout & block diagram

BOTM

ABCDFEAUX

36 35 34 33 32 29 28 26

ADFG

ADAGC

ADIN

ADFMSECSLEDTEWBLADJ

31 30 27 25

PEAK 37

RF 38

RFAGC 39

AGCI 40

NC 41

NC 42

ADDC 43

NC 44

TEGC 45

RFO 46

MORFI 47

MORFO 48

2.Pin function

No.

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Symbol

APCREF

OPOUT

SWDT

XSTBY F0CNT

EQADJ

3TADJ

I/O

I J

VC

A B C D E F

PD

APC

GND

OPIN

SCLK

XLAT

VREF

I/O I/O

Vcc

AGC,EQ

Peak,Bottom Detector

0/-2dB

RF Amp

123456789101112

I

J

Function

I-V converted RF signal I input

I

I-V converted RF signal J input

I

Vcc/2 voltage output

O

A current input for main beam servo signal

I

B current input for main beam servo signal

I

C current input for main beam servo signal

I

D current input for main beam servo signal

I

E current input for side beam servo signal

I

F current input for side beam servo signal

I

Reflection light q'ty monitor signal input

I

Laser APC output

O

Ref. voltage input for laser power intensity setting

I

Ground

-

Ope. amp output terminal

O

21dB ope. amp input terminal

I

Serial data input terminal

I

Shift clock input terminal

I

Latch input terminal

I

Stand by setting terminal

I

F0 count setting terminal

I

Reference voltage output terminal

O

EQ IF setting terminal BPF3T IF setting terminal Power supply

-

ADIP Amp

FE Amp

3T Detector

ABCD Amp

TE

SE

ADIN

AUX

FE

RF

NC NC

NC

RFO

I-V Amp

E

D

I/O

O

O O

I

O O O O O O O

-

I

-

I/O

-

I

O

I

O

I-V Amp APC

A

B

25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

Pin No.

C

Symbol

WBLADJ

CSLED

ADFM

ADAGC

ADFG

ABCD BOTM PEAK

RFAGC

AGCI

ADDC

TEGC

MORFI

MORFO

VC

TE/SE Amp

24 Vcc

23 3TADJ

22 EQADJ

21 VREF

20 F0CNT

19 XSTBY

18 XLAT

CPU Command I/F

OP Amp

F

PD

APC

APCREF

Function

BPF3T IF setting terminal Tracking error signal output terminal Sled error signal LPF capacitor connect terminal Sled error signal output terminal ADIP FM signal output terminal ADIP signal completer input terminal ADIP AGC capacitor connect terminal ADIP binary signal output I3 output/temp.signal output Focus error signal output

Reflection light q'ty signal output for main beam servo detector

RF/ABCD bottom-hold signal output RF/ABCD peak-hold signal output RF equalizer output RFAGC capacitor connection RFAGC input Non connect Non connect ADIP amp. feedback circuit capacitor connection Non connection TE amp. gain switching RF amp. output Groove RF signal AC-coupled input Groove RF signal output

17 SCLK

16 SWDT

15 OP IN

14 OP OUT

13 GND

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