Jvc UXV 30 Service Manual

Page 1

UX-V30

JVB
SERVICE MANUAL

MICRO COMPONENT SYSTEM

UX-V30

(JK\U

(0 i

53%

@m mi

Area Suffix

[flangffi UF --------------------- China

DIGITAL AUDIO

Contents
Safety precautions """""""""""""" 1'2 Maintenance of |aser pickup ___________ 1_19
Important for laser pFOdUCtS """""" 1-3 Rep|acement Of laser pickup ___________ 1-1 9
Disassembly method """""""""" 14 Description of major ICs _________________ 120
Main adjustment .......................... 1.14
Flow of functional operation

until TOC read ------- 1-1 8

This service manual is printed on 100% recycled paper. No_20888

COPYRIGHT (6 2000 VICTOR COMPANY OF JAPAN, LTD.
1 Dec. 2000

Page 2

UX-V30

-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 (A) 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 areturn path to the chassis, to a known good earth ground. Any leakage
current must not exceed 0.5mA AC (r.m.s.)

0 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 1,5009 10W resistor paralleled by
a 0.15uF AC-type capacitor between an exposed

AC VOLTMETER
metal part and a known good earth ground. (Having 1000
Measure the AC voltage across the resistor with the 7 ohms/volts,
AC voltmeter. or more sensitivity)
Move the resistor connection to eachexposed metal °
part, particularly any exposed metal part having a 0.15uF AC TYPE
return path to the chassis, and meausre the AC .
voltage across the resistor. Now, reverse the plug in -II- 33:21?
the AC outlet and repeat each measurement. voltage W): V > each exposed
measured Any must not exceed 0.75V AC (r.m.s.). 15009 10W metal part.

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

- 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.

A CAUTION Burrs formed during molding may be left over on some parts of the chassis. Therefore,

1-2

pay attention to such burrs in the case of preforming repair of this system.

Page 11

UX-V30

«Cassette Mechanism Section»

I Removing the Playback/Recording & Eraser

5.
6

7.
8.

9.

.While shifting the trigger arms seen on the right

.When the flywheel R is rotated in counterclockwise

Cassette mechanism

Head ( See Figs. 1 and 2)

side of the head mount in the arrow direction,
turn the flywheel R in counterclockwise direction
until the head mount has gone out with a click
(See Fig. 1).

Flywheel Fl

direction, the Playback/Recording & Eraser head
will be turned in counterclockwise direction from the
position in Fig. 2 to that in Fig. 3.

. At this position, disconnect the flexible PC. board
(outgoing from the Playback/Recording & Eraser head) Head mount Trigger arm
from the connector CN31 on the head amplifier & Fig.1
mechanism control P.C. board.
.After dismounting the FPC holder, remove the flexible Playback/Recording &
P.C. board. eraser hyead Spring "a"
Remove the flexible P.C. board from the chassis base. Frexible
. Remove the spring Afro behind the Playback/Recording board A Trigger arm

& Eraser head.

Loosen the reversing azimuth screw retaining the Playback
/Recording & Eraser head.

Take out the Playback/Recording & Eraser head from the
front of the head mount.

The PIayback/Ftecoring & Eraser head should also be

removed similarly according to Steps 1 ~ 8 above. CN31

Head amplifier & mechanism Flywheel R
control P.C. board

I Reassembling the Playback/Recording & Eraser

CON

5.

. Reassemble the playback head from the front of the head

. Fix the reversing azimuth screw.
. Set the spring "a" from behind the Playback/Recording &

Head Fig. 2

Playback/Recording & Reversing azimuth

mount to the position as shown in Fig. 3. eraser head screw

C.)

Eraser head. Spring "at. Head

. Attach the flexible P.C. board to the chassis base, and fix mount
it with the FPC holder as shown in Fig.3. .
The Playback/Recording & Eraser head should also be :rexgle

oar

reassembled similarly to Step 1 ~ 4 above.

CN31
Head amplifier &

mechanis control
RC. board

FPC holder

Fig. 3

Page 16

UX-V30

l Tape Recorder Section

Measurement Standard Ad'ustin
Items conditions Measurement method Values polsitiong
Confirmation Test tape 1 Playback the test tape VTT703L (8kHz) Maximum Adjust the head
of head angle :VTT703L (8kHz) 2 With the recording & playback mechanism, output azimuth screw
Measurement output adjust the head azimuth screw so that the only when the
terminal forward and reverse output levels become head has been
:Speaker terminal maximum. After adjustment, lock the head changed.
Speaker R azimuth at least by half turn.
(Load resistance: 49) 3 In either case, this adjustment should be
: Headphone terminal performed in both the forward and reverse
directions with the head azimuth screw.
Confirmation Test tape Adjust VR37 so that the frequency counter Tape speed VR301
of tape speed :VT712 (3kHz) reading becomes 2,940~3,090Hz i when of deck
Measurement output playing back the test tape VT712 (3kHz) with 32,940 ~
terminal playback and recording mechanism after 3,090H2
: Headphone terminal ending forward winding of the tape.
l Reference Values for Confirmation Items
Measurement Standard Ad'ustin
Items conditions Measurement method Values position:
Difference Test tape When the test tape VT712 (3kHz) has been 6.0Hz or Head azimuth
between the :VT712 (3kHz) played back with the recording and playback less screw
forward and Measurement output mechanism at the beginning of forward
reverse speed terminal winding, the frequency counter reading of the
: Speaker terminal difference between both of the mechanism
Speaker R should be 6.0Hz or less.
(Load resistance: 4 Q)
Measurement output
terminal
: Headphone
Wow & flutter Test tape When the test tape VT712 (3kHz) has been 0.25% or
:VT712 (3kHz) played back with the recording and playback less
Measurement output mechanism at the beginning of forward (WRMS)

terminal
: Headphone terminal

winding, the frequency counter reading of
wow & flutter should be 0.25% or less
(WRMS).