Jvc PC XT3 Service Manual

Page 1

JVC
ERVICE MANUAL

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PC-XT3 B/E/G \s\xw,lrccscrviccmanuals.info

Contents

Page
Safety Precautions .......................................... 2
Safety Precautions about PC-XT3 ..................... 3
Features .........................................
Specifications ............

Instructions (Extract) ..
Location of Main Parts

7 Removal of Main Parts and Enclosure Parts List . 19
Main Adjustment ............................ 28

IIEIEIEIEIEE

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DIGITAL AUDIO
Area suffix
B ......... U.K.
E . Continental Europe
G ...... Germany

IE Block Diagram ..........
Wiring Connections

[E Standard Schematic Diagram and

Location of P.C. Board Part . 44
E] Electrical Parts List ..................... . 52
IE Illustration 01 Packing and Packing Parts List . 58
Accessories .................................................... 59

No. 1837
August 1991

Page 2

PC-XTS B/E/G

- 1 Safety Precautions

l. The 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. 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 of the produm
should not be made. Any design alterations or additions will void the manufacturer's warranty and will further
relieve the manufacturer or responsibility for personal injury or property damage resulting therefrom.

3. Many electrical and mechanical parts in the product 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 (A) on the schematic diagram and Parts List in Service Manual. The use
of a substitute replacement which does not have the same safety characteristics as the recommended replace-
ment pan shown in the Parts List in 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 pans, 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 pro-

duct 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 part 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 0.5 mA AC (r.m.s.).

I ' 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 n 10 W resistor paralleled by a 0.15 F AC-type capacitor

between an exposed metal part and a known good earth ground.

, , A V LTMETER
Measure the AC voltage across the resustor With the AC E (Hives; 1000 ohms/v0"
voltmeter. or more sensitivity.)
Move the resistor connection to each exposed metal a
_°T-

part. particularly any exposed metal part having a return
path to the chassis. and measure the AC voltage across
the resistor. Now, reverse the plug in the AC outlet and Place this probe
repeat each measurement. Any voltage measured must w on each "posed
not exceed 0.75 V AC (r.m.s.). 1500f) 10W metal part.

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

0.15 («F AC TYPE

Good earth ground

- Warning

. This equipment has been designed and manufactured to meet international safety standards.

. it is the legal responsibility of the repairer to ensure that these safety standards are maintained.
. Repairs must be made in accordance with the relevant safety standards.

. It is essential that safety critical components are replaced by approved parts.

. lf mains voltage selector is provided, check setting for local voltage.

assure-

IMPORTANT (In the United Kingdom)
Mains Supply (Ac 240 V'\/, 50 Hz only)

IMPORTANT

Do not make any connection to the Larger Terminal coded E or If these colours do not correspond with the terminal Identifications
Green. The wire: In the mains load are coloured in accord-nae or your plug, connect II follows:
! with the following code: Blue wlre to terminal coded N (Neutral) or coloured Black.
Brown wire to terminal coded L (Live) or coloured Red.

Blue to N (Neutral) or Black If in doubt - consult a competent electrician.
Brown to L (Live) or Red

2 (No. 1837)