Hitachi DVW 1 U Service Manual

Page 1

TK No.9006E

HITACHI
SERVICE MANUAL

DV-W1 U

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DIGITAL VIDEO DIGITAL AUDIO VIDEO CD

SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT

DVD PLAYER - CD RECORDER

May 2000 Digital Media Products Division, Tokai

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SAFETY PRECAUTIONS

NOTICE:
Comply with all cautions and safety related notes
located on or inside the cabinet and on the chassis.

1. When replacing a chassis in the instrument, all the
protective devices must be put back in place, such as
barriers, non-metallic knobs, adjustment and
compartment covers/shields, isolation resistors/
capacitors, etc.

2. When service is required, observe the original lead-
ress. Extra precautions should be taken to assure
correct lead dress in the high voltage circuit.

3. Always use the manufacturer's replacement
components. Especially critical components as
indicated on the circuit diagram should not be
replaced by other manufacturer's. Furthermore,
where a short-circuit has occurred. replace those
components that indicate evidence of overheating.

4. Before returning an instrument to the customer, the
service technician must thoroughly test the unit to be
certain that it is completely safe to operate without
danger of electrical shock, and be sure that no
protective device built into the instrument by the
manufacturer has become defective or inadvertently
defeated during servicing. Therefore, the following
checks should be performed for the continued
protection of the customer and service technician.

Leakage Current Cold Check

With the AC plug removed from the AC120V, 60Hz
source, place a jumper across the two plug prongs.
Turn the AC power switch on. Using an insulation
tester (DCSOOV), connect one lead to the jumpered

AC plug and touch the other lead to exposed metal
parts (antennas, screwheads, metal overlays,

control shafts. etc.). particularly any exposed metal part
having a eturn path to the chassis. Exposed metal
parts having a return path to the chassis should have a
minimum resistor reading of 0.3 Mohm and a maximum
resistor reading of 5 Mohm. Any resistor value below
or above this range indicates an abnormality which
requires corrective action. Exposed metal parts not
having a return path to the chassis will indicate an open
circuit.

Leakage Current Hot Check

Plug the AC line cord directly into a AC120V, 60Hz
outlet (do not use an isolation transformer for this
check).

Turn the AC power switch on. Using a Leakage
Current Tester", measure for current from all
exposed metal parts of the cabinet (antennas,
screwheads, metal overlays, control shaft, etc.),
particularly an exposed metal part having a return
path to the chassis. to a known ground (earth) (water
pipe, conduit, etc.). Any current measured must not
exceed 0.5 mA.

LEAKAGE CURRENT

TESTER
(READING
SHOULD NOT \
BE ABOVE \

0.5mA)

DEVICE

TEST ALL EXPOSED

METAL SURFACES
¢/\. 2-WIRE CORD
ALSO TEST WITHPLUG GRTOUND
REVERSED(USING AC (EARTH)
ADAPTER PLUG AS
REQUIRED)

AC Leakage Test

ANY MEASUREMENTS NOT WITHIN THE LIMITS
OUTLINED ABOVE ARE INDICATIVE OF A POTENTIAL
SHOCK HAZARD AND MUST BE CORRECTED
BEFORE RETURNING THE UNIT TO THE CUSTOMER.

PRODUCT SAFETY NOTICE

Many electrical and mechanical parts have special safety-
related characteristics. These are often not evident from
visual inspection nor can the protection afforded by them
necessarily be obtained by using replacement
components rated for a higher voltage, wattage, etc.
Replacement parts which have these special safety
characteristics are identified in this Service Manual.
Electrical components having such features are identified
by marking with aAon the schematics and the parts list
in this Service Manual. The use of a substitute
replacement component which does not have the same
safety characteristics as the HITACHI recommended
replacement one, shown in the parts list in this Service
Manual, may create shock, fire, or other hazards. Product
safety is continuously under review and new instructions
are issued from time to time. For the latest information,
always consult the current HITACHI Service Manual. A
subscription to, or additional copies for, HITACHI Service
Manual may be obtained at a nominal charge from
HITACHI SALES CORPORATION.

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Notes When Using Service Manual I

The following shows the contents to be noted when using service manual:

1. Value units used in parts list

Certain symbols are indicated below for value units of
resistors, capacitors and coils in parts list. When you read
them note the following regular indications:

Parts Indication in list Regular indication
Resistor KOHM ........................................... kQ
F ................................................. F
Capacnor U
PF -- - pF
.. . H
Coil UH
MH ............................................... mH

2. Values in schematic diagrams

The values, dielectric strength (power capacitance) and
tolerances of the resistors (excluding variable resistors)
and capacitors are indicated in the schematic diagrams
using abbreviations.

[Resistors]

Item Indication

No indication ................................... Q

Va|ue K ................................................... k9
No indication - 25%

Tolerance (All tolerances other than 15% are

indicated in schematic diagrams)
No indication ............................ 1/8W
(1/16W for leadless resistors without

Power _ . ,

. indication)
capacnance

All capacitances other than the above
are indicated in schematic diagrams.

[Capacitors]

Item Indication
N 'n ' ' n-
Value OI dicatio
P ................
_ _ NO indication .............................. 50V
Dielectric . _
(All dielectric strengths other than 50V
strength . _ _ _ _
are indicated in schematic diagrams)
[Coils]
Item Indication

Value

3. Identifications of sides MB in

circuit board diagrams

1) Board having a pattern on one side and parts on
both sides.
Side A: Shows discrete parts, viewed from the
pattern side.
Side B: Shows leadless parts, viewed from the
pattern side.
2) Board having patterns on both sides and parts on
both sides.
Side A: Shows parts and patterns which can be
seen when the case is opened.
Side B: Shows parts and the pattern on the back of
side A.

4 Table for indexing locations of parts

This table shows locations of each part on circuit board
diagrams. The locations are indicated using the guide
scales on the external lines of diagrams.

1) One diagram indicated for each board

Symbol Parts

No. Location

IC <- Type of part
|01201 2 A

i .- E

Zone "A" on board diagram
- Zone "2" on board diagram

Circuit No.

2) Two diagrams indicated for each board

Symbol Parts
No. Location
10 - Type of part
IC1201 A - 2 A
T T T
I l-Zone A" on board
Circuit No. diagram
A: Shows side A-Zone 2" ° board
B: Shows side B d'agram