Panasonic Omnivision VHS PV-C2780, Service Manual

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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 BoardLayout, Exploded Views and Replacement
Parts List. It is essential that these critical parts should be
replaced with manufacturer's specified parts to prevent X-
RADIATION, shock, fire, or other hazards. Do not modify the
original design withoutpermission of manufacturer.
2. An Isolation Transformer should always be used during the
servicing of Combination VCR whose chassis is not isolated from
the AC power line. Use a transformer of adequate power rating as
this protects thetechnician from accidents resulting in personal
injury from electrical shocks. It will also protect Combination VCR
from being damaged by accidental shorting that may occur during
servicing.
3. When servicing, observe the original lead dress, especially the
lead dress in the high voltage circuits. 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, shield, and isolation R-C
combinations are properly installed.
5. Before turning the receiver on, measure the resistance between B+
line and chassis ground. Connect (-) side of an ohmmeter to the B
+ lines, and (+) side to chassis ground. Each lineshould have
more resistance than specified, as follows :
B+ Line
Minimum Resistance
125 V
1 k (Cold chassis ground)
27 V
180 (Cold chassis ground)
17 V
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