JVC MXKB4 - Service Manual Immediate Download

SERVICE MANUAL

No.MB254

2004/7

COMPACT COMPONENT SYSTEM

MB254

2004

MX-KB4

TABLE OF CONTENTS

PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21

FM MODE

FM /AM

AUX

SLEEP

STANDBY/ON

SOUND

MODE

RHYTHM AX

FADE

MUTING

VOLUME

PROGRAM /RANDOM

REPEAT

TAPE

REMOTE CONTROL

CA-MXKB4

SP-MXKB4

Area suffix

UW ----------- Brazil,Mexico,Peru

UJ ---------------------- U.S.Military

1-2 (No.MB254)

SPECIFICATION

Design and specifications are subject to change without notice.

Amplifier

Output Power

140 W per channel, min. RMS, driven into 6

at 1kHz, with no more than

10% total harmonic distortion (IEC 268-3)

Input

Sensitivity/Impedance

(1 kHz)

AUX IN:400 mV/50 k

Speaker terminals

6 - 16

Phones

- 1 k

Cassette Deck

Frequency Response

15 mW/ch output into 32

Type I (NORMAL)

63 Hz - 12 500 Hz

Wow And Flutter

0.15% (WRMS)

CD Player

CD Capacity

3 CDs

Dynamic Range

85 dB

Signal-To-Noise Ratio

85 dB

Wow And Flutter

Unmeasurable

Tuner

FM Tuner Tuning Range

87.50 - 108.00 MHz (at AM9 kHz channel space)

87.5 - 108.0 MHz (at AM10 kHz channel space)

AM Tuner Tuning Range

531 kHz - 1710 kHz (at AM9 kHz channel space)

530 kHz - 1710 kHz (at AM10 kHz channel space)

Unit

Dimensions

270 mm

× 306 mm × 456 mm (W/H/D)

Mass

Approx. 8.6 kg

Speaker Specifications

SP-MXKB4 (each unit)

Type

3-way bass-reflex type

Speaker Unit

Woofer:20 cm cone

× 1

Mid:5cm cone

× 1

Tweeter:2 cm dome

× 1

Power Handling Capacity

140 W

Impedance

Frequency Range

45 Hz - 22,000 Hz

Sound pressure level

87 dB/W·m

Dimensions

257 mm

× 321 mm × 261 mm (W/H/D)

Mass

Approx. 4.9 kg

Power Specifications

Power Requirements

AC 110/127/220/230-240V , adjustable with voltage selector, 50/60 Hz

Power Consumption

140 W (power on mode) 22 W (in Standby mode)

(No.MB254)1-3

SECTION 1

PRECAUTION

1.1

Safety Precautions

(1) This design of this product contains special hardware and

many circuits and components specially for safety purpos-

es. 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 per-

formed by qualified personnel only.

(2) Alterations of the design or circuitry of the product should

not be made. Any design alterations of the product should

not be made. Any design alterations or additions will void

the manufacturers warranty and will further relieve the

manufacture of responsibility for personal injury or property

damage resulting therefrom.

(3) Many electrical and mechanical parts in the products have

special safety-related characteristics. These characteris-

tics are often not evident from visual inspection nor can the

protection afforded by them necessarily be obtained by us-

ing replacement components rated for higher voltage, watt-

age, etc. Replacement parts which have these special

safety characteristics are identified in the Parts List of Ser-

vice 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 charac-

teristics 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 reassem-

bling.

(5) Leakage shock hazard testing

After reassembling the product, always perform an isola-

tion check on the exposed metal parts of the product (an-

tenna 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, particular-

ly any exposed metal part having a return path to the

chassis, to a known good earth ground. Any leakage cur-

rent 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

per volt or more sensitivity

in the following manner. Connect a 1,500

10W resistor

paralleled by a 0.15

µF AC-type capacitor between an ex-

posed 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 measure the AC voltage across

the resistor. Now, reverse the plug in the AC outlet and

repeat each measurement. Voltage measured any must

not exceed 0.75 V AC (r.m.s.). This corresponds to 0.5

mA AC (r.m.s.).

1.2

Warning

(1) This equipment has been designed and manufactured to

meet international safety standards.

(2) It is the legal responsibility of the repairer to ensure that

these safety standards are maintained.

(3) Repairs must be made in accordance with the relevant

safety standards.

(4) It is essential that safety critical components are replaced

by approved parts.

(5) If mains voltage selector is provided, check setting for local

voltage.

1.3

Caution

Burrs formed during molding may be left over on some parts

of the chassis.

Therefore, pay attention to such burrs in the case of pre-

forming repair of this system.

1.4

Critical parts for safety

In regard with component parts appearing on the silk-screen

printed side (parts side) of the PWB diagrams, the parts that are

printed over with black such as the resistor (

), diode (

)

and ICP (

) or identified by the "

" mark nearby are critical

for safety. When replacing them, be sure to use the parts of the

same type and rating as specified by the manufacturer.

(This regulation dose not Except the J and C version)

Good earth ground

Place this

probe on

each exposed

metal part.

AC VOLTMETER

(Having 1000

ohms/volts,

or more sensitivity)

1500

10W

0.15 F AC TYPE

1-4 (No.MB254)

1.5

Preventing static electricity

Electrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is discharged, can destroy the laser

diode in the traverse unit (optical pickup). Take care to prevent this when performing repairs.

1.5.1

Grounding to prevent damage by static electricity

Static electricity in the work area can destroy the optical pickup (laser diode) in devices such as laser products.

Be careful to use proper grounding in the area where repairs are being performed.

(1) Ground the workbench

Ground the workbench by laying conductive material (such as a conductive sheet) or an iron plate over it before placing the

traverse unit (optical pickup) on it.

(2) Ground yourself

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

(3) Handling the optical pickup

· In order to maintain quality during transport and before installation, both sides of the laser diode on the replacement optical

pickup are shorted. After replacement, return the shorted parts to their original condition.

(Refer to the text.)

· Do not use a tester to check the condition of the laser diode in the optical pickup. The tester's internal power source can easily

destroy the laser diode.

1.6

Handling the traverse unit (optical pickup)

(1) Do not subject the traverse unit (optical pickup) to strong shocks, as it is a sensitive, complex unit.

(2) Cut off the shorted part of the flexible cable using nippers, etc. after replacing the optical pickup. For specific details, refer to the

replacement procedure in the text. Remove the anti-static pin when replacing the traverse unit. Be careful not to take too long a

time when attaching it to the connector.

(3) Handle the flexible cable carefully as it may break when subjected to strong force.

(4) I t is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not turn it.

1.7

Attention when traverse unit is decomposed

*Please refer to "Disassembly method" in the text for the pickup unit.

· Apply solder to the short land sections before the flexible wire is disconnected from the connecto on the servo board. (If the flexible

wire is disconnected without applying solder, the pickup may be destroyed by static electricity.)

· In the assembly, be sure to remove solder from the short land sections after connecting the flexible wire.

Conductive material

(conductive sheet) or iron palate

(caption)

Anti-static wrist strap

CD PCB

Short round

CN601

(No.MB254)1-5

1.8

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 CD,MD and DVD 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 defeated. 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 here in may result in

hazardous radiation exposure.

REPRODUCTION AND POSITION OF LABELS

CAUTION : Visible and Invisible

laser radiation when open and

interlock

failed

defeated.

AVOID DIRECT EXPOSURE TO

BEAM.

(e)

VARNING

Synlig

och

osynling laserstrålning när

den öppnas och spärren är

urkopplad.

Betrakta

strålen.

(s)

VARO : Avattaessa ja suojalukitus

ohitettuna tai viallisena olet alttiina

näkyvälle

näkymättömälle

lasersäteilylle.

Vältä

säteen

kohdistumista suoraan itseesi. (f)

ADVARSEL : Synlig og usynlig

laserstråling når maskinen er

åben eller interlocken fejeler.

Undgå direkte eksponering til

stråling.

(d)

Please use enough caution not to

see the beam directly or touch it

in case of an adjustment or operation

check.

CLASS 1

LASER PRODUCT