Jvc RX 450BK Service Manual

Page 1

Fix-4508K
RX-450LB

77a: GUM
441"} 34 QAGO £42 TON For Service Manuals Contact
9775 W (5;; ml munrmon TECHNICAL sgnvwzs
Tag; 3 Cherry Tree Rd. Chmnor
; [75 0x00 OX9 40!
m Tet- 018444551 94 Fac- oywasasu
Wrerqurwmmfl
Page
Safety Precautions .............................. 1-2 Connection Diagram ........
Instruction Book Schelatic Diagrams
OCR may --------------------------------- 13 (URX'4SOBK Tuner Section ------------- av Insertion
Rennval Procedures ----------------------------- 1-4 (2)RX-450LBK Tuner Section --------------- Insertion
FM/HH/Lw Tuner AIignIent Procedures ----------- 15 (3)Logic Section ------------------------ Insertion
Pouer Alplifier IdIing Current Adjustment 1-6 (Power Alplifier Section --------------- Insertion
Function of ICs on the Pre~AmpliEier PCB 1-6 Parts List ---------------- Separate-value Insertion
Internal Block Diagrals of Major LSI [Cs --------- I~7
No. 297(

Feb 198

Page 2

Fix-4508K
RX -4 SOLBK

Safety Precautions

1. The design of this product contains special hardware and

many circuits and components specially for safety pur-
poses.
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. Service should be
performed by qualified personnel only.

2. Alterations of the design or circuitry of the product
should not be made. Any design alterations or additions
will void the manufacturers warranty and will further
relieve the manufacturer of responsibility for personal
injury or property damage res "

_ .g therefromu

3. Many electrical and mechanical parts in the product
have special safety-related characteristics. These charac-
teristics are often not evident from visual inspection nor
can the protection afforded by them necessarily be ob-
tained 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 the Service Manual. Electrical components
having such features are identified by shading on the
schematics and by l A 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 recom-
mended replacement part shown in the Parts List of
the,$ervice 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 sepa-
rated from live parts, high temperature parts, moving
pans 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
the they have been returned to normal, after reassembl-

mg.

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 omlet.
Using a Leakage Current Tester", measure the
leakage current from each exposed metal part of the
cabinet, particularly any exposed metal pan having a
return path to the chassis, to a known good earth
ground. Any leakage current must not exceed 0.5 mA
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 1,500 9
10 W resistor paralleled by a 0.15 uF 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 pan 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. Any
voltage measured must not exceed 0.75 V AClr.m.s.).
This corresponds to 0.5 mA AClrms).

AC VOLTMETER
@ (Having 1000 ohms/volt.
or more sensitivrty.)
a c

0.15;} AC YVPE

Place this probe

r
l
l
l

I Before inserting the paper plug, please check that the voltage selector's setting corresponds with
Ithe line voltage in your area. If it. doesn't. be sure to reset. the voltage selector before operating

this equipment.

The voltage selector may be located on the rear or button of the unit. or underneath the platter.

:CAUTIUN : Before setting the voltage selector to the proper voltage. disconnect the power plug.

1J7 1M.» 7Q7fll

4% on each exposed
isoon row metal part.
Good earth ground
CHECK THE VOLTAGE SELECTOR'S SETTING - -

(Except for U.S.A., Canada. Australia. U.K. and Continental Europe)

-_-._-_____J

) .

Page 47

lX-4SOBK
lX-450LBK

ANTENNAS
ANTENNEN
ANTENNES

Use oi CATV cable

Venuendung des Kabel-TV-Kabels
Utilisation dun cable CATV
Gebuilt van de CATV-Kabel

Use flat cable CATV

FM external antena

ANTENNES
ANTENAS

Used along with CATV antenna contra

I unit

UKW-Aulienantenne
Antenne externe FM
FM-burtenantenne
Antena exterior de FM

(Rater to the instruction book at CATV antenna control unit)
Verwenmmg mll einer Kabel-TV-Antennensteuereinheit

(Siehe Beatenungsanlettung der Antennensteuereinheit)
Utilisées avec un boitler de oemmande dantenne CATV
(Se reporter au manuel oinslructtons du homer de commande

o'antenne CATV)

Wordl samen met cert CATVantenneregeleenhetd gebruikt

CARTV cable
KabeI-TV-Kabet
Céble catv
catv-kabel
Cable CATV

lZie tevens de georuiksaanwrizing van de CATV-antennaegeleen-

held)

Se utitlzan junta con la unldad dc control dam: CATV
(Reliérase al manual de instruccrones de la unload de control

as antena CATV)

;

To AV antenna terrmnal

An AV-AntenenanshluB

Vers borne d'antenne AV

Near de AV-antenneaansluiting

Hacla el terminal as antena AV

Fig. 8
ADD. 8
Nb. 8

Fig.5
Ahhs
m9

Fig. 10
AM). 10
Mb. 10

V0.2970)

Fig.6
Mk6
MES

AM anlennas (Fig. 3. 9)

O How to assemble the AM loop antenna (Fig 8)
Snap the loop antenna onto the stand. then slide ll
as shown until lirmty held in place.

- When too much noise occurs (Fig. 9)

Change the direction oi the loop antenna orreinstail
it in a position that gives best reception

0 AM external antenna (Fig 10)

ll AM reception is not good. connect an external
AM antenna (single-me antenna) to the AM-
ANTENNA terminal

Notes:

. It the provided loop antenna is not set up and
its wires attached. or the antenna wires touch
the rear panel, it will be impossible to receive
AM broadcasts.

- When installing an AM extremal antenna, have
the AM loop antenna connected

- It the AM loop antenna is too close to the
speaker terminals, it may came noise and
should be moved away truth the rear panel.

FM antennas

- 75-ohm antenna wtth coaxial lead (Fig. 1t)
Loosen the screws on the bracket we insert the
cable ll'llO the ring from below. Then connect the
stripped core to the upper terminal. The bracket
ring works as the ground terminal.

0 Feed antenna (Fig. 12)
Connect to the 300mm terminal
Take care that the wires oi the leeder antenna do
not touch any other terminal. -

For W. Germany (Fig; 13)

0 The PM wire antenna provtded can be corneal-3d
to the 75-ohm coax-l rack temporarily

- 75-ohm antenna wtth coaxial type contractor (DIN
45 332)
Canned to the 75~ohm terminal

F-type converter plug (attached to CATV

antenna control unit)

-When using the FM antenna, attach to this
apparatus,

F-Steckeradapter (zur KaheLW-Antennen-

- Fm uKW-Antenne diesen Adapter verv
wenden

Fiche de conversron type F (fixée au banter de

oommande dantenne CATV)

- En utilisant l'anlenna FM' ltxer a cet appareil.

F-type konversiestekker [bevestigd aan de

CATV»antenneregeleenherd.)

vOp dlt apparaat aansluiten wanneer de FM-
antenne gebrulkl worot,

Clavria convertioora ltpo F (Mada a la unidad da

control de antena CATV)

vCuando utltice la antena De FM, liela a esta
aparato.

w steuereinhert hetestlgt)

Usrng-F-type connector

a..." a... ...l.. Verwendung elnes F-Anschlusses
Utilisant un connecteur de type F
Bi] genrurk van de Hype aansluiting
Uso del conector tipo F

AM-Anlenrlen (Abb. 8, 9)

0 Anbnngung oer AM-Ftahmenanteme (Abb. 8)
Die Rahmenantenne am Hatter lestdriicken und
oann wte gezeigt verschreben. um sicheren Sitz zu
gewehrtetsten,

u Wenn zu viele Slégerausche emptangen warden
(Abb 9)

Die Richtung tier Rahmenantenne ver'a'noern oder
in einer Position anhringen. die einen besseren
Emplang ergibt,

- MW-AuBenantenne (Abe, 10)

Wenn der MW-Emptang nioht gut ist eine MW-
AuBenantenne (Einzeldrahtantenne) an den AM
ANTENNA-AnschluB anschlieflen,

Hinweise:

. Wenn die mitgelielerte Rahamenantenne nlchl
angebmeht und angeschlossen ist otter die
Antennendrihte die Rfickplalle beriihren, is!
MW-Empiang nicht mégileh.

0 Die MW-Flahrnenanterine muB auch ange
schlossen bleiben, wenn cine MW-AuBenarl-
lenne angeschlossen wird.

I Wenn die MW-Rahmenantenne sich zu nahe
an den Laulsprecheransmifissen belindel.
kfinnen Slfirgerfiusche auflrelent Daher dle
Rahrnenantenne magiiehst weit von der
Hijackplatle entleml anbringen.

UKW-Antennen

0 75-Ohm-Antenne mll Koaxlalkabel (Abb ll)
Die Schrauben an der Halterung losen und das
Kabei von unten in den Fling einliihren.
Darin den abtsollerlelt lnnenlerter an die obere
Klemme anschielien Der Halterungsnng client als
Erdungsklemme.

' Speiseantenne (AD!) 12)
An die Goo-Ohm-Klernme anschliefien.
Daraul achten. daB die Kabel der Speiseantenne
die anderen Anschliisse nicht bertihren.

Flil' 8RD (Abb. 13)

ODie mitgelielerte UKW-Drahtanlenne kann zeit-
wetlig an die 75-OhrrvKoaxialbuohse ange~
schlossen verden.

o 75-Ohm-Anteme mil Koaxialstecker (DIN 45 382i

An den 7&Otm-Amchlufl anschlleflerl

r
i