JVC GR-SXM250US, Руководство по обслуживанию

Страница: 3 / 75

(No.86721)1-3
SECTION 1
PRECAUTIONS
1.1 SAFTY PRECAUTIONS
Prior to shipment from the factory, JVC products are strictly in-
spected to conform with the recognized product safety and elec-
trical codes of the countries in which they are to be
sold.However,in order to maintain such compliance, it is equally
important to implement the following precautions when a set is
being serviced.
1.1.1 Precautions during Servicing
(1) Locations requiring special caution are denoted by labels
and inscriptions on the cabinet, chassis and certain parts of
the product.When performing service, be sure to read and
comply with these and other cautionary notices appearing in
the operation and service manuals.
(2) Parts identified by the symbol and shaded ( ) parts
are critical for safety.
Replace only with specified part numbers.
NOTE :
Parts in this category also include those specified to
comply with X-ray emission standards for products
using cathode ray tubes and those specified for com-
pliance with various regulations regarding spurious
radiation emission.
(3) Fuse replacement caution notice.
Caution for continued protection against fire hazard.
Replace only with same type and rated fuse(s) as specified.
(4) Use specified internal wiring. Note especially:
• Wires covered with PVC tubing
• Double insulated wires
• High voltage leads
(5) Use specified insulating materials for hazardous live parts.
Note especially:
• Insulation Tape
• PVC tubing
• Spacers
• Insulation sheets for transistors
• Barrier
(6) When replacing AC primary side components (transformers,
power cords, noise blocking capacitors, etc.) wrap ends of
wires securely about the terminals before soldering.
Fig.1
(7) Observe that wires do not contact heat producing parts
(heatsinks, oxide metal film resistors, fusible resistors, etc.)
(8) Check that replaced wires do not contact sharp edged or
pointed parts.
(9) When a power cord has been replaced, check that 10-15 kg
of force in any direction will not loosen it.
Fig.2
(10) Also check areas surrounding repaired locations.
(11) Products using cathode ray tubes (CRTs)In regard to such
products, the cathode ray tubes themselves, the high volt-
age circuits, and related circuits are specified for compliance
with recognized codes pertaining to X-ray emission. Conse-
quently, when servicing these products, replace the cathode
ray tubes and other parts with only the specified parts. Under
no circumstances attempt to modify these circuits.Unautho-
rized modification can increase the high voltage value and
cause X-ray emission from the cathode ray tube.
(12) Crimp type wire connector
In such cases as when replacing the power transformer in
sets where the connections between the power cord and
power trans former primary lead wires are performed using
crimp type connectors, if replacing the connectors is un-
avoidable, in order to prevent safety hazards, perform care-
fully and precisely according to the following steps.
• Connector part number :E03830-001
• Required tool : Connector crimping tool of the proper
type which will not damage insulated parts.
• Replacement procedure
a) Remove the old connector by cutting the wires at a
point close to the connector.
Important : Do not reuse a connector (discard it).
Fig.3
b) Strip about 15 mm of the insulation from the ends of
the wires. If the wires are stranded, twist the strands
to avoid frayed conductors.
Fig.4
c) Align the lengths of the wires to be connected. Insert
the wires fully into the connector.
Fig.5
d) As shown in Fig.6, use the crimping tool to crimp the
metal sleeve at the center position. Be sure to crimp
fully to the complete closure of the tool.
Fig.6
e) Check the four points noted in Fig.7.
Fig.7
Power cord
cut close to connector
15 mm
Connector
Metal sleeve
1.2
5
2.0
5.5
Crimping tool
Not easily pulled free
Crimped at approx. center
of metal sleeve
Conductors extended
Wire insulation recessed
more than 4 mm