PT2-E/G AVC1-U
SAFETY PRECAUTIONS
NOTICE: Comply with all cautions and safety-related notesLeakage Current Hot Check
located on or inside the cover case and on the chassis or plasmaThis check must be done considering the AVC or the PDP
module.monitor as one instrument each.
WARNING: Since the chassis of the AVC unit and Plasma PanelWith any of the instruments completely reassembled (being
unit is connected to both sides of the AC power supply duringthe instrument either the AVC center or the PDP monitor), plug
operation, whenever the receiver is plugged in, service shouldthe AC line cord directly into a 120V AC outlet. (Do not use an
not be attempted by anyone unfamiliar with the precautionsisolation transformer during this test.) Use a leakage current
necessary when working on this type of receiver.tester or a metering system that complies with the American
National Standards Institute (ANSI) C101.0 Leakage Current
1. When service is required, an isolation transformer should befor Appliances. In the case of the PDP monitor set the AC
inserted between power line and the receiver before anyswitch first in the ON position and then in the OFF position,
service is performed on a ?HOT? chassis receiver.measure from a known earth ground (metal waterpipe,
conduit, etc.) to all exposed metal parts of the instrument
2. When replacing a chassis in the receiver, all the protective(antennas, handle bracket, metal cabinet, screw heads,
devices must be put back in place, such as barriers, non-metallic overlays, control shafts, etc.), especially any exposed
metallic knobs, insulating cover-shields, and isolationmetal parts that offer an electrical return path to the chassis.
resistors, capacitors, etc.Any current measured must not exceed 0.5 milliamps.
Reverse the instrument power cord plug in the outlet and
3. When service is required, observe the original lead dress.repeat test.
4. Always use manufacturer?s replacement components. Critical
components as indicated on the circuit diagram should not be(READING
replaced by another manufacturer?s. Furthermore, where aSHOULD NOT
LEAKAGE
BE ABOVE 0.5mA)
short circuit has occurred, replace those components thatCURRENT
TESTER
indicate evidence of over heating.DEVICE
UNDER
TEST
5. Before returning a serviced receiver to the customer, theTEST ALL
service technician must thoroughly test the unit to be certainEXPOSED
that it is completely safe to operate without danger of electricalMETAL SURFACES
shock, and be sure that no protective device built into the3-WIRE CORDEARTH
GROUND
receiver by the manufacturer has become defective, or
ALSO TEST WITH PLUG
inadvertently defeated during servicing.
REVERSED
(USING AC ADAPTER
Therefore, the following checks should be performed for thePLUS AS REQUIRED)
continued protection of the customer and service technician.
AC LEAKAGE TEST
Leakage Current Cold Check
With the AC plug removed from the 120V AC 60Hz source,ANY MEASUREMENTS NOT WITHIN THE LIMITS OUTLINED
place a jumper across Line 1 and Line 2 of the three plugABOVE ARE INDICATIVE OF A POTENTIAL SHOCK
prongs, do not connect with the third prong, which is physicalHAZARD AND MUST BE CORRECTED BEFORE
ground.RETURNING THE RECEIVER TO THE CUSTOMER.
Using an insulation tester (DC500V), connect one of its leads
to the AC plug jumper and touch with the other lead each
exposed metal part (antennas, screwheads, metal overlays,
control shafts, etc.), particularly any exposed metal part
having a return path to the chassis shoud have a minimum
resistor reading of 4Mź and a maximum resistor reading of
7.14Mź .Any resistance value below or above this range
indicates an abnormality which requires corrective action. An
exposed metal part not having a return path to the chassis will
indicate an open circuit.
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ACEC
HITACHI
