Jvc MXJ 76 Service Manual

Page 2

MX-J70/MX-J76/MX-J75R

-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 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 Sen/ice Manual. Electrical components having such features are identified by
shading on the schematics and by (L) 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 current 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 15009 10W resistor paralleled by
a 0.1511 F AC-type capacitor between an exposed

metal part and a knovm good earth ground. fixgflgggm
Measure the AC voltage across the resistor with the 7 ohms/Wm

AC voltmeter. or more sensitivity)
Move the resistor connection to each exposed metal

part, particularly any exposed metal part having a 0_15uF AC TYPE

return path to the chassis, and measure the AC .
voltage across the resistor. Now reverse the plug in -H- 5:33:21?
the AC outlet and repeat each measurement voltage WV each exposed
measured any must not exceed 0.75 V AC (r.m.s.). 15009 10W metal part.

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

-Warmng
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." mains voltage selector is provided, check setting for local voltage.

A 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 pretorming repair of this system.

1-2

Page 48

MX-J 70/MX-J76/MX-J75R

Joint bracket B

226

I Removing the rolling Panel Assembly
(See Fig.27)

1. Remove the two Y screws attaching the rolling panel
assembly.

2. Remove the rolling panel assembly while pulling outward

the left and right hooks attaching the rolling panel
assembly.

I Removing the operation switch Board
(See-Fig.28 and 29)

1. Remove the six Z screws attaching the cover and the
bracket.

2. Release the two t tabs fitted to the bracket, and pull out
the left and right panel holders.

3. Remove the two A screws attaching the operation switch
board.

I Removing the Drive Motor (See Fig.30 and 31)
1. Remove the two B screws and the two C screw attaching
2. Pull out the gear shaft A upward.

3. Remove the motor belt.

C Joint bracket

Rolling panel assembly
Fig.27

Hook

Panel holder

Bracket
Panel holder

Cover

Fig.28

operation switch Board

Motor belt
Gear shaft A

Drive motor

Fig.31

Page 51

l Removing the CD loading mechanism
assembly($ee Fig.10)

11While turning the cams R1 and R2 assembly in the
arrow direction H , align the shaft I" of the CD
loading mechanism assembly to the position shown in
2. Figt10.
Remove the tour screws 6 retaining the CD loading
mechanism assembly.

I Removing the CD traverse mechanism
(See Fig.11 and 12)

1. For dismounting only the CD traverse mechanism
without removing the CD loading mechanism assembly,
align the shaft J" 01 the CD loading mechanism
assembly to the position shown Fig.11 while turning the
cam R1 and R2 assembly in the arrow direction K" .

2. By raising the CD loading mechanism assembly in the
arrow direction L" , remove the assembly from the
lifter unit

Cam R1, R2 assembly

- g
.1 03MB Arrow
/ a» C/ K

J \_ 5 °

I Removing the CD pick unit
(See Fig.13 )

1. Move the cam gear in the arrow direction 3 .Then, the
CD pickup unit will be moved in the arrow direction b .

2. According to the above step, shift the CD pickup unit to
the center position.

3. While pressing the stopper retaining the shaft in the
arrow direction c , pull out the shaft in the arrow
direction d .

4. After dismounting the shaft from the CD pickup unit,
remove the CD pickup unit

MX-J70/MX-J76/MX-J75R

Cams R1, R2 assembly

Al'fOW

I
CD loading mechanism assembly
Fig.10

CD Pickup unit

CD loading
mechanism

2-29