JVC JXS555 - Service Manual Immediate Download

SERVICE MANUAL

AV SELECTOR

No.70251

Mar. 2001

2001 VICTOR COMPANY OF JAPAN, LTD.

Printed in Japan

0103(S)

VICTOR COMPANY OF JAPAN, LIMITED

COMMUNICATION NETWORK BUSINESS UNIT, 1644, SHIMOTSURUMA, YAMATO-SHI, KANAGAWA-KEN, 242-8514, JAPAN

JX-S555 (J)

No.70251

JX-S555(J)

No.

70251

Contents

Safety Precautions ...............................

Main Parts Locations ............................ 3

Disassembly of Parts ............................ 4

Connection Diagram ............................. 6

Circuit Description ................................

Adjustments ......................................... 11

Position of ICs and Adjustment Points ....... 12

Servicing Guidelines ............................ 13

Block View Inside IC ............................. 17

Design and specifications are subject to change without notice.

JX-S555(J)

2 (No. 70251)

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.).

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.

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

(No. 70251) 3

JX-S555(J)

Main Parts Locations

AUDIO 2 board

AUDIO 1 board

Front 1 board

Bottom chassis

Front panel ass'y

Front 2 board

Rear panel

MAIN board

Jack board

Top cover

JX-S555(J)

4 (No. 70251)

Disassembly of Parts

(No. 70251) 5

JX-S555(J)

Note : For the positions of the connectors, see the connection

diagram (page 6).

Removing the top cover

1. Remove the two screws 3 retaining the top cover 1 from the

rear panel 2, then remove the four screws 4 retaining the

top cover from the side panels.

2. Slightly open out the bottoms of the side skirts

I of the top

cover 1 as shown in the figure, then pull the top cover straight

upward

II . Do not remove the top cover by pulling it up in an

oblique direction.

Removing the Audio 1 Board

5 and Audio 2

Board

1. Remove the top cover 1.

2. From the rear panel 2, remove the six screws 7 retaining the Audio 1 board 5 and the six screws 7 retaining the

Audio 2 board 6.

3. Gently remove the Audio 1 board 5 and then unplug the connectors CN809 and CN810 from it.

4. Gently remove the Audio 2 board 6 and then unplug the connectors CN807 and CN808 from it.

Removing the Main Board

1. Remove the top cover 1, then the Audio 1 board 5 and finally the Audio 2 board 6.

2. From the rear panel 2, remove the nineteen screws C retaining the Main board B.

3. Unplug the connectors CN1, CN3, CN804 and CN811 (and the wire from the Front Panel Assembly D )on the Main

board B .

4. Unplug the connector CN901 (in the power supply circuit) on the Main board B.

5. Remove the two clamping screws E on the Main board B.

6. Disengage the three claws of the locking card spacer F on the Main board B, then remove the Main board by lifting

it in an oblique direction.

Removing the Rear Panel

1. Remove the top cover 1.

2. Unplug the connector CN901 (in the power supply circuit) on the Main board B.

3. Remove the twelve screws 7 retaining the Audio 1 board 5 and the Audio 2 board 6, then remove the nineteen screws

CretainingtheMainboardB.

4. Remove the three screws H retaining the bottom chassis G and the rear panel 2.

5. Gently remove the rear panel 2.

(Take care of the AC power cord I connected to the rear panel 2.)

Removing the Front Panel Assembly

1. Remove the top cover 1.

2. Remove the three retaining screws J from the bottom of the Front Panel Assembly D.

3. Disengage the fittings between the side panels of the Front Panel Assembly D with the bottom chassis G, then

gently pull out the Front Panel Assembly D from the bottom chassis G toward the front.

4. Unplug the connectors CN1, CN3, CN804 and CN811 from the Main board B.

5. Remove the Front Panel Assembly D.

Removing the Front 1 Board

K, Front 2 Board L

L and Jack Board 8

1. Remove the top cover 1 and the Front Panel Assembly D.

2. Remove the two screws M retaining the Front 1 board K, five screws M retaining the Front 2 board L and the two screws

9 retaining the Jack board 8.

3. Remove the Front 1 board K, the Front 2 board L and the Jack board 8.