Panasonic Quasar Omnivision PV-V4021-K, Руководство по обслуживанию, Страница: 3 / 146

- Main C.B.A. (Ref. No. E10)
When ordering these, be sure to confirm the model number printed on the Model No. Label and order
the proper parts according to the replacement parts list.
2. SAFETY PRECAUTIONS
GENERAL GUIDELINES
1. IMPORTANT SAFETY NOTICE
There are special components used in this equipment which are
important for safety. These parts are marked by in the Schematic
Diagrams, Circuit Board Layout, Exploded Views and Replacement
Parts List. It is essential that these critical parts should be replaced
with manufacturer’s specified parts to prevent shock, fire or other
hazards. Do not modify the original design without permission of
manufacturer.
2. An Isolation Transformer should always be used during the servicing
of VCR whose chassis is not isolated from the AC power line. Use a
transformer of adequate power rating as this protects the technician
from accidents resulting in personal injury from electrical shocks. It
will also protect VCR from being damaged by accidental shorting that
may occur during servicing.
3. When servicing, observe the original lead dress. If a short circuit is
found, replace all parts which have been overheated or damaged by
the short circuit.
4. After servicing, see to it that all the protective devices such as
insulation barriers, insulation papers shields are properly installed.
5. After servicing, make the following leakage current checks to prevent
the customer from being exposed to shock hazards.
LEAKAGE CURRENT COLD CHECK
1. Unplug the AC cord and connect a jumper between the two prongs on
the plug.
2. Measure the resistance value, with an ohmmeter, between the
jumpered AC plug and each exposed metallic cabinet part on the
equipment such as screwheads, connectors, control shafts, etc. When
the exposed metallic part has a return path to the chassis, the reading
should be between 1 M and 5.2 M . When the exposed metal does
not have a return path to the chassis, the reading must be infinity.
LEAKAGE CURRENT HOT CHECK
(See figure 1.)
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