JVC MXSK-1 Service manual

SECTION 1 PRECAUTION

1.1Safety Precautions

1.2Warning

1.3Caution

1.4Critical parts for safety

1.5Preventing static electricity

1.6Handling the traverse unit (optical pickup)

1.7Attention when traverse unit is decomposed

3.1Main body

4 (1)

SERVICE MANUAL

COMPACT COMPONENT SYSTEM

MX-SK1

M X - S K 3

DISC

SELECT

VOL

UME

ACTIVE

BASS EX.

				SELECT
1	2	3
	REMOTE CONTROL
			EJECT EJECT
		SP-MXSK1	CA-MXSK1	SP-MXSK1

COMPACT

Area suffix

DIGITAL VIDEO

DIGITAL AUDIO

EE --------- Russian Federation

TABLE OF CONTENTS

1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5 3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-30 5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-34

No.MB207

2004/4

SPECIFICATION

Amplifier section

Output Power	MAIN SPEAKERS	64 W per channel min. RMS both channels driven into
		6 Ω at 1 kHz with no more than 0.9% total harmonic
		distortion.

Audio input sensitivity/Impedance	AUX	400 mV/50 kΩ
(Measured at 1 kHz with tape record-
(Measured at 1 kHz with tape record-	MIC	3 mV/10 kΩ
ing signal 300 mV)
	Tuner
FM tuning range		87.50 MHz to 108.00 MHz

AM tuning range	At 9 kHz intervals	531 kHz to 1 710 kHz

	At 10 kHz intervals	530 kHz to 1 710 kHz

	CD player
CD capacity	3 CDs

Dynamic range	85 dB

Signal-to-noise ratio	90 dB

Wow and flutter	Immeasurable

	Cassette deck
Frequency response Normal (type I)	50 Hz to 14 000 Hz

Wow and flutter	0.15% (WRMS)

	General
Power requirement	AC 110 V / AC 127 V / AC 220 V / AC 230 V to AC 240 V (adjustable with the voltage selector)

Power consumption	50 Hz / 60 Hz

	100 W (at operation)

	20 W (on standby)

Dimensions (approx.)	270 mm x 306 mm x 433.5 mm (W/H/D)

Mass (approx.)	9.2 kg

	Speaker Specifications
Type	3-Way 3 Speaker Bass-Reflex (Magnetically-Shielded Type)

Speakers	Main woofer	15cm cone x 1

	Mid Range	5.0cm cone x 1

	Tweeter	2.0cm dome x 1

Power Handling Capacity	80 W

Impedance	6 Ω

Frequency Range	42 Hz to 30 000Hz

Sound Pressure Level	84 dB/W.m

Dimensions (W x H xD)	215mm x 306 mm x 243 mm

Mass	3.4 kg

Design & specifications are subject to change without notice.

1-2 (No.MB207)

(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 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 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 reassembling.

(5)Leakage shock hazard testing

After reassembling 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, 1,000Ω per volt or more sensitivity in the following manner. Connect a 1,500Ω 10W resistor paralleled by a 0.15µF 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 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.).

AC VOLTMETER (Having 1000 ohms/volts,

or more sensitivity)

0.15F AC TYPE

	Place this
	probe on
1500 10W	each exposed
1500 10W	metal part.

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.

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)

(No.MB207)1-3

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.

1.5.1Grounding to prevent damage 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.

(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.

(caption)

Anti-static wrist strap

Conductive material (conductive sheet) or iron palate

(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)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.

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

•Apply solder to the short land sections before the flexible wire is disconnected from the connecto on the CD servo board. (If the flexible wire is disconnected without applying solder, the CD 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.

1-4 (No.MB207)

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

(No.MB207)1-5

SECTION 3

DISASSEMBLY

Speaker board

Front panel assembly

3.1.1Removing the metal cover (See Fig.1~3)

(1)Remove the six screws A on the back of the main body.

(2)Remove the four screws B on each side of the body.

(3)Remove the metal cover from the body by lifting the rear part of the cover.

CAUTION :

Do not break the front panel tab fitted to the metal cover.

Fig.1

Fig.2

Fig.3

1-6 (No.MB207)

3.1.2Removing the CD fitting (See Fig.4~6)

•Prior to performing the following procedure, remove the metal cover.

ATTENTION :

Be sure to remove the CD tray fitting before removing the CD changer unit.

(1)Press the STANDBY button. Press the OPEN/CLOSE button to eject the CD trey.

(2)Move the CD trey fitting upward and release the joint a.

(3)Press the OPEN/ CLOSE button to insert the tray.

CD tray

STANDBY / ON button

OPEN / CLOSE button

	Fig.4
CD tray fitting	Joint a

Joint a

Fig.5

CD tray

Fig.6

(No.MB207)1-7

3.1.3 Removing the CD fitting (See Fig.5~7)

•How to eject the CD trey without turning on power.

(1)Turn the loading pulley gear marked b from the back of the CD changer unit as shown in Fig.7 and draw the CD tray toward the front.

(2)Move the CD tray fitting upward and release the joint a.

(3)Push and insert the CD tray manually.

3.1.4Removing the CD changer unit (See Fig.8 ~10)

•Prior to performing the following procedure, remove the metal cover and the CD fitting.

(1)Disconnect the wire from connector CN13 on the main board.

(2)On the right side of the body, disconnect the card wire from connector CN651 on the CD board in the bottom of the CD changer unit.

(3)Remove the four screws D attaching the CD changer unit on both sides of the body.

(4)Remove the three screws E on the back of the body.

(5)Move the CD changer unit in the direction of the arrow with pulling the rear panel and the front panel assembly outward.

CD changer unit

Rear panel

	Main borad	CN651
Front panel assembly	(CN13)	CN651
	(CN13)

	Fig.8

1-8 (No.MB207)

Marked b

Loading pulley gear

Fig.7

CD changer unit

Rear panel

	Main borad
CN651	(CN13)	Front panel assembly
		Front panel assembly

Fig.9

Rear panel

Fig.10

3.1.5Removing the CD board (See Fig.11~13)

•Prior to performing the following procedure, remove the metal cover and the CD changer unit.

Caution :

Before disconnecting the card wire extending from the CD pickup, make sure to solder the short-circuit point on the CD pickup(Fig.12 and 13). If you do not follow this instruction, the CD pickup may be damaged.

(1)Remove the four screws F attaching the CD board on the bottom of the CD changer unit.

(2)Turn and move the CD board as shown in Fig.12.

(3)Disconnect the wire from the CD mechanism board.

(4)Solder the short-circuit point on the CD pickup section.

(5)Disconnect the card wire from CN601 on the CD board.

Caution :

When reassembling, unsolder the short-circuit point after connecting the card wire to CN601 on the CD board.

CD changer unit

CD board

CD mechanism board

Fig.11

CD mechanisum board

Short round (Short-circuit)

CD board (CN601)

Fig.12

Card wire

Pick up

Short round (short-circuit)

Fig.13

(No.MB207)1-9

3.1.6 Removing the front panel assembly (See Fig.14~16)

•Prior to performing the following procedure, remove the metal cover and the CD changer unit.

(1)Disconnect the card wire from the connector CN315, CN316 and CN870 on the main board.

(2)Disconnect the wire from connector CN702 on the speaker board and remove the band attaching the wire to the main board.

(3)Disconnect the wire from the connector CN214 on power transformer board.

(4)Remove the two screws G attaching the front panel assembly on the bottom of the body.

(5)Remove the two joints d and e on the lower part of the sides using a screwdriver, and remove the front panel assembly toward the front.

Front panel assembly

	Main board	CN316
	CN870	CN316
	CN870
	CN315

Power transformer board CN214

Fig.15

Front panel assembly

Fig.16

1-10 (No.MB207)

3.1.7Removing the tuner pack assembly (See Fig.17~18)

• Prior to performing the following procedure, remove the metal
cover and the CD changer unit.
(1) Disconnect the card wire from the connector CN1 on the	Rear panel
tuner pack assembly on the right side of the body.

(2)Remove the two screws H on the rear panel on the back of the body.

Tuner pack (CN1)

AUX & surround board

Fig.17

Rear panel

Fig.18

(No.MB207)1-11

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