Jvc MXK 1 Service Manual

Page 1

MX-K1

JVC

SERVICE MANUAL

COMPACT COMPONENT SYSTEM

MX-K1

@EEfi

DIGITAL AUDIO
SP-MXK1 CA-MXK1 SP-MXK1
Area Suffix
J ------------------- U.S.A.
C ----------------- Canada
Contents
Safety precautions ----------------------- 1-2 Flow of functional
Important for laser products ------------ 1-3 operation until TOC read - 1-20
Preventing static electricity ------------- 1-4 Maintenance of laser pickup - 1-21
Disassembly method --------------------- 1-5 Replacement of laser pickup ........... 1-21
Adjustment method ----------------------- 1-18 Description of major le - 1-22
No.20942

COPYRIGHT (c 2001 VICTOR COMPANY OF JAPAN, LTD.
May. 2001

Page 2

MX-K1

-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 Service Manual. Electrical
components having such features are identified by shading on the schematics and by (/t\,) 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.

0 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 Q10W resistor paralleled by a 0.1 51.1 F AC-type capacitor

between an exposed metal part and a known good earth ground. AC VOLTMETER
Measure the AC voltage across the resistor with the AC a (Having1000
voltmeter. ohms/volts,

Move the resistor connection to eachexposed metal part, c more sens'mm')

particularly any exposed metal part having a return path to
the chassis, and meausre the AC voltage across the resistor. 0'15: AC TYPE

Now, reverse the plug in the AC outlet and repeat each -"| Placehis
measurement. Voltage measured any must not exceed 0.75 V W . ~ gaitheeigosed
AC (r.m.s.). This corresponds to 0.5 mA AC (r.m.s.). 15009 10W metal part.
Good earth ground
- Warning A CAUTION

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 (h) and ICP (Q) or identified by the (N
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.
(Except the J and C version)

Page 13

I Removing the cassette deck mechanism
(See Fig.21)

- Priorto performing the following procedure, remove
the top cover.

- Also remove the CD changer unit.

- Also remove the front panel assembly.

1.Remove the five screws "0" retaining the cassette
deck mechanism from the back of the front panel
assembly.

I Removing the earphone jack PCB
(See Fig.22)

- Priorto performing the following procedure, remove
the top cover

- Also remove the CD changer unit.

- Also remove the front panel assembly.

1 . Remove the screw with the washer, "P" that retains

the earphone jack PCB from the back of the front
panel assembly.

I Removing the control/FL PCB
(See Fig.23)

- Priorto performing the following procedure, remove
the top cover.
- Also remove the CD changer unit.

1. Remove the three screws "0" that retain the
control/FL PCB from the back of the front panel
assembly.

MX-K1

Front panel
assembly

I

O

Front panel
assembly

Earphone jack
PCB

Front panel

assem

is a

bly

Control/FL
PCB

Page 19

lArrangement of adjusting positions

MX-K1

Cassette deck mechanism
(Front side)
PB Head REC/PB Head ON?
(Deck-A) (Deck-B) '_ in
D Laot
U » U » FM VT voltage
measurement point
Head azimuth screw Head azimuth screw AM VT voltage
(Forward side) (Forward side) . measurement point
Head screw Head screw R5
R3

l Tape recorder section

L2 Main P.C.B. Ass'y
Antenna coil 030 coil

Measurement output
terminal

: Left and Right
speaker output
(6-ohm loaded)

or

Headphone Output
(32-ohm loaded)

output and both output of L / R is in 3dB.
3. Put on the screw lock paint after alignments.

Items Measurement Measurement method Standard Adjusting

conditions Values posttlons

Cassette Head Test tape 1 . Playback the test tape VT703 (1 OKHz) or equivalent. Maximum output Head azimuth
Azimuth Alignments :VT703 (10kHz) 2. Adjust the head azimuth screw to obtain maximum screw

Adjust the head
azimuth screw only
when the head has
been changed.

3.Adjust the IFI' Block T1 obtain to maximum output.
(Adjust the SSG output to out of AGC range.)

Recording Bias Test tape 1.|nsert the recording tape in deck-B. 80kHz+/-3kHz Bias coil: L301
Frequency Alignment :TYPE 11 AC-514 2. Starting the recording.
Measurement output 3. Adjust the oscillation frequency to 80KHz+/-3KHz by Use the High-
terminal core of Oscillation coil of L301. Impedance Probe for
: Erase head terminal Frequency counter
(CN308 8-Pin) input.
I Tuner section
Items Measurement Measurement method Standard Adjusting
conditions values posttlons
AM Tracking Input signal 080 coil adjustment V.T OSC/Antenna coil
Alignments :530kHz 1.Set the Signal Generator signal to 530KHz the feed to : 1 .40V+/-0.05V : L2
Measurement point Loop Antenna. Adjust the osc coil
: Resistor R3 (AM) 2.Fteceiving the signal and the adjust the OSC coil (L2) only when the AM coil
Resistor R6 (FM) obtain the V.T is 1.40V +/-0.05V. block has been
input" él'g'nél """""" A niénné'c'éii 'c'h'ec'K b'r'eiclj'u's'tr'n'ér'it """""""""""" ll/l'a'iinit'ii'n' """" changed.
: 600kHz 1.Change the receiving frequency to 600KHz. sensitivity
2.Adjust the Antenna coil ( L2 ) obtain maximum sensitivity.
(Adjust the SSG output to out ot AGC range.)
AM IFT Alignments Input signal 1 . Set the receiving frequency to 53OKHz. Maximum output IFT (T1)
: 530kHz 2. Feed the 450KH2 signal to AM IF input. Adjust the ll-l'only

when the IFT block has

been changed.

Note: The adjustment of CD section is not required.

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