Jvc DRE 34 BK Service Manual

Page 1

DR-E34BK
DR -E34LBK

.JVI:
SERVICE MANUAL

DR-E34BK
MODEL No. DR-E34LBK

Contents

Page Page
Safety Precautions ............................... 2 Adjustment Procedures (Tuner) .r .. 1-29
Instruction Book ............ 3 Connection Diagrams ................ ., 1-30
Disassembly Procedures . . 1-16
Explanation of System Control IC . . 1-17 Schematic Diagrams ..................................... Insertion
Description of Major ICs , 1-18 Printed Circuit Boards . Insertion
Explanation of Other ICs . 1-23 Block Diagrams . . Insertion

Internal Connections of the FL play Tube .
Adjustment Procedures (Cassette Deck) .......

. 1-25 Parts List ..

.. . Separate-voiume Insertion
. 1»26

No. 20162
Mar, 1990

Page 2

DR-E34BK
DR-E34LBK

Fo

rel

usi
saf

4. Th

Do

L 7 _.

nSafety Preca utions_-

1. The design of this product contains special hardware and many circuits and components specially for safety purposes.

manufacturer. Replacement parts must be identical to those used in the original circuits. Service should be per-
formed 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 manufacturer's warranty and will further

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

are identified by shading on the schematics and by ( ,' l on the Parts List in the Service Manual. The use of a sub-
stitute replacement which does not have the same safety characteristics as the recommended replacement part shown
in the Parts List of Service Manual may create shock, fire, or other hazards,

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 iack, control shafts, etc.) to be sure the product
is safe to operate without danger of electrical shock,

r continued protection, no changes should be made to the original design unless authorized in writing by the

ieve the manufacturer of responsibility for personal injury or property damage resulting therefrom.

ng replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special
ety characteristics are identified in the Parts List of Service Manual. Electrical components having such features

e leads in the products are routed and dressed with ties, clamps, tubings, barriers and the like to be separated from

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 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.).
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 sensi-
tivity in the following manner. Connect a 1,500 9 10W resistor paralleled by a 0-15l1F AC-type capacitor be-
tween an exposed metal part and a known good earth ground. 7 7
Measure the AC voltage across the resistor with the [- AC VOLTMETER
AC voltmeter. L5 (Having 1000 ohms/volt,

_ _ or more sensmvrty.)
Move the resrstor connection to each exposed metal
part, particularly any exposed metal part having a

U
Good earth ground

l
return path to the chassis, and measure the AC volt- ° "F AC we
age across the resistor. Now, reverse the plug in the P l a! place this probe
AC outlet and repeat each measurement. Any voltage -7L 4, ._ ,L .4. on each exposed
measured must not exceed 0.75 VAC (r.m.s.). This Isoon row metal pan.

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

L

TWarning- - , 7 -

.Th
Iti
.Re
.lti

weenie-r

'l-2 (No. 20162)

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

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

5 essential that safety critical components are replaced by approved parts.

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