Denon PMA-A100, Service Manual

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2
SAFETY PRECAUTIONS
The following check should be performed for the continued protection of the customer and service technician.
LEAKAGE CURRENT CHECK
Before returning the unit to the customer, make sure you make 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 unit is defective.
Be sure to test for leakage current with the AC plug in both polarities, in addition, in each power ON, OFF and STANDBY
mode, if applicable.
CAUTION Please heed the points listed below during servicing and inspection.
◎
Heed the cautions!
Spots requiring particular attention when servicing, such
as the cabinet, parts, chassis,etc., have cautions indicated
on labels. be sure to heed these causions and the
cautions indicated in the handling instructions.
◎
Caution concerning electric shock!
(1) An AC voltage is impressed on this set, so touching
internal metal parts when the set is energized could
cause electric shock. Take care to avoid electric
shock, by for example using an isolating transformer
and gloves when servicing while the set is energized,
unplugging the power cord when replacing parts, etc.
(2) Tere 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 manufacturing parts
from sheet metal, there may in some rare cases be burrs
on the edges of parts which could cause injury if
fi
ngers
are moved across them. Use gloves to protect your hands.
◎
Only use designated parts!
The set's parts have specific safety properties (fire
resistance, voltage resistance, etc.). For replacement
parts, be sure to use parts which have the same
poroperties. In particular, for the important safety parts
that are marked
z on wiring diagrams and parts lists, be
sure to use the designated parts.
◎
Be sure to mount parts and arrange the wires
as they were originally!
For safety seasons, some parts use tape, 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 wores omsode amd clamps
are used to keep wires away from heating and high
voltage parts, so be sure to set everything back as it was
originally.
◎
Inspect for safety after servicing!
Check that all screws, parts and wires removed or
disconnected for servicing have been put back in their
original positions, inspect that no parts around the area
that has been serviced have been negatively affected,
conduct an inslation 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 turn the power switch on.
Using a 500V insulation resistance tester, check that the
inplug and the externally exposed metal parts (antenna
terminal, headphones terminal, input terminal, etc.) is
1M
Ω or greater. If it is less, the set must be inspected and
repaired.
Many of the electric and structural parts used in the set
have special safety properties. In most cases these
properties are difficult to distinguish by sight, and using
replacement parts with higher ratings (rated power and
withstand voltage) does not necessarily guarantee that
safety performance will be poreserved. Parts with safety
properties are indicated as shown below on the wiring
diagrams and parts lists is this service manual. Be sure to
replace them with parts with the designated part number.
(1) Schematic diagrams ......Indicated by the
z
mark.
(2) Parts lists ......Indicated by the
z
mark.
Using parts other than the designated
parts could result in electric shock,
fi
res
or other dangerous situations.
CAUTION Concerning important safety
parts