Denon AVR-4520, Руководство по обслуживанию

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6
SAFETY PRECAUTIONS
The following items should be checked for continued protection of the customer and the service technician.
LEAKAGE CURRENT CHECK
Before returning the set to the customer, be sure to carry out either (1) a leakage current check or (2) a line to chassis
resistance check. If the leakage current exceeds 0.5 milliamps, or if the resistance from chassis to either side of the
power cord is less than 460 kohms, the set is defective.
Be sure to test for leakage current with the AC plug in both polarities, in addition, when the set's power is in each state (on,
off and standby mode), if applicable.
CAUTION
Please heed the following cautions and instructions during servicing and
inspection.
◎
Heed the cautions!
Cautions which are delicate in particular for servicing
are labeled on the cabinets, the parts and the chassis,
etc. Be sure to heed these cautions and the cautions
described in the handling instructions.
◎
Cautions concerning electric shock!
(1) An AC
voltage is impressed on this set, so if
you touch internal metal parts when the set is
energized, you may get an electric shock. Avoid
getting an electric shock, by using an isolating
transformer and wearing gloves when servicing
while the set is energized, or by unplugging the
power cord when replacing parts, for example.
(2) There are high voltage parts inside. Handle with
extra care when the set is energized.
◎
Caution concerning disassembly and
assembly!
Through great care is taken when parts were
manufactured from sheet metal, there may be burrs
on the edges of parts. The burrs could cause injury if
fingers are moved across them in some rare cases.
Wear gloves to protect your hands.
◎
Use only designated parts!
The set's parts have sp
ecific safety properties (fire
resistance, voltage resistance, etc.). Be sure to use
parts which have the same properties for replacement.
The burrs have the same properties. In particular, for
the important safety parts that are indicated by the
z
mark on schematic diagrams and parts lists, be sure to
use the designated parts.
◎
Be sure to mount parts and arrange the wires
as they were originally placed!
For safety seasons, some parts use tapes, tubes or
other insulating materials, and some parts are mounted
away from the surface of printed circuit boards.
Care is also taken with the positions of the wires by
arranging them and using clamps to keep them away
from heating and high voltage parts, so be sure to set
everything back as it was originally placed.
◎
Make a safety check after servicing!
Check that all screws, parts and wires removed or
disconnected when servicing have been put back in
their original positions, check that no serviced parts
have deteriorate the area around. Then make an
insulation check on the external metal connectors and
between the blades of the power plug, and otherwise
check that safety is ensured.
(Insulation check procedure)
Unplug the power cord from the power outlet,
disconnect the antenna, plugs, etc., and on the power.
Using a 500V insulation resistance tester, check that
the insulation resistance value between the inplug and
the externally exposed metal parts (antenna terminal,
headphones terminal, input terminal, etc.) is 1MΩ or
greater. If it is less, the set must be inspected an
d
repaired.
Many of the electric and the structural parts used in
the set have special safety properties. In most cases
these properties are difficult to distinguish by sight, and
the use of replacement parts with higher ratings (rated
power and withstand voltage) does not necessarily
guarantee that safety performance will be preserved.
Parts with safety properties are indicated as shown
below on the wiring diagrams and the parts list in this
service manual. Be sure to replace them with the parts
which have the designated part number.
(1) Schematic diagrams .......Indicated by the z mark.
(2) Parts lists .......Indicated by the z mark.
The use of parts other than the
designated parts could cause electric
shocks, fires or other dangerous
situations.
CAUTION Concerning important safety
parts