Hitachi HTDK 150 EBS Service Manual

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SM0151

HITACHI

45/

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SERVICE MANUAL
MANUEL D ENTRETIEN
WARTUNGSHANDBUCH

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3

HTDK150EBS

CAUTION:

Before servicing this chassis, it is important that the service technician
read the "Safety Precautions and "Product Safety Notices in this
service manual.

ATTENTION:

Avant d'effectuer lentretien du chéassis, le technicien doit lire les
«Precautions de sécurité» et les «Notices de sécurité du produit»
presentés dans le present manuel.

VORSICHT:

Vor Offnen des Gehauses hat der Service-Ingenieur die
,,Sicherheitshinweise und ,,Hinweise zur Produktsicherheit in diesemi

Wartungshandbuch 2u lesen.

JULY 2001

Data contained within this
Service manual is subject to
alteration for improvement.

Les données fournies dans le

present manuel dentretien
peuvent faire lobjet de
modifications en vue de

perfectionner le produit.

Die in diesem
Wartungshandbuch enthaltenen
Spezifikationen kénnen sich
zwecks Verbesserungen andern.

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ENGLISH

SAFETY PRECAUTIONS

WARNING: The following precautions must be observed.

ALLPRODUCTS

Before any service is performed on the chassis an
isolation transformer should be inserted between the
power line and the product.

1. When replacing the chassis in the cabinet, ensure
all the protective devices are put back in place.

2. When service is required, observe the original
lead dressing. Extra precaution should be taken to
ensure correct lead dressing in any high voltage
circuitry area

3. Many electrical and mechanical parts in

HITACHI 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 by marking with a
A on the schematics and the replacement parts
list.
The use of a substitute replacement component
that does not have the same safety characteristics
as the HITACHI recommended replacement one,
shown in the parts list, may create electrical
shock, fire, X-radiation, or other hazards.

4. Always replace original spacers and maintain lead
lengths. Furthermore, where a short circuit has
occurred, replace those components that indicate
evidence of overheating.

5. Insulation resistance should not be less than 2M
ohms at 500V DC between the main poles and
any accessible metal parts.

6. No flashover or breakdown should occur during
the dielectric strength test, applying 3kV AC or
4.25kV DC for two seconds between the main
poles and accessible metal parts.

7. Before returning a serviced product 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. The
service technician must make sure that no
protective device built into the instrument by the
manufacturer has become defective, or
inadvertently damaged during servicing.

CEMARK

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HITACHI products may contain the CE mark on
the rating plate indicating that the product
contains parts that have been specifically
approved to provide electromagnetic
compatibility to designated levels.

When replacing any part in this product, please
use only the correct part itemised in the parts list
to ensure this standard is maintained, and take
care to replace lead dressing to its original state,
as this can have a bearing on the electromagnetic
radiation/immunity.

HCTURETUBE

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The line output stage can develop voltages in
excess of25kV; if the E.H.T. cap is required to be
removed, discharge the anode to chassis via a
high value resistor, prior to its removal from the
picture tube.

High voltage should always be kept at the rated
value of the chassis and no higher. Operating at
higher voltages may cause a failure of the picture
tube or high voltage supply, and also, under
certain circumstances could produce X-radiation
levels moderately in excess of design levels. The
high voltage must not, under any circumstances,
exceed 29kV on the chassis (except for projection
Televisions).

The primary source of X-radiation in the product
is the picture tube. The picture tube utilised for
the above mentioned function in this chassis is
specially constructed to limit X-radiation. For
continued X-radiation protection, replace tube
with the same type as the original HITACHI
approved type

Keep the picture tube away from the body while
handling. Do not install, remove, or handle the
picture tube in any manner unless shatterproof
goggles are worn. People not so equipped should
be kept away while picture tubes are handled

LASERS

If the product contains a laser avoid direct exposure to
the beam when the cover is open or when interlocks are
defeated or have failed.