Technics SU-V45A - Repair and Adjustment

@
The
power
supply
for
this
unit
varies
depending
upon
the
areas.
Also,
the
parts
used
for
power
supply
are
different.
So,
refer
to
the circuit
diagram
and replacement
parts
list.
* [XA] area is provided with voltage selector and AC outlets.
* 240V (50/60HZz) for Australia and United Kingdom.
* 220V (50/60Hz) for Continental Europe.
* 110V/127V/220V/240V (50/60Hz) for other [XA] area.
* Phono input capacitance is about 100pF.
Suggestions
Notes:
©To record sounds from a compact disc, press the input
selector marked “‘CD”.
The compact-disc-direct switch is for listening only; it
cannot be used to select the compact disc as a recording
source.
elf noise is very annoying while listening to an FM or AM
broadcast, switch OFF the video disc player, compact-disc
player and turntable.
eSwitch OFF the video disc player power if noise is
excessive while listening to an audio tape, compact disc or
regular
phono
disc.
©Do
not
press
the
left
tape-monitor
selector
to
the
“tape
1/DA tape” position while two tape decks are being used
for recording or while tape deck 2 is being used for
recording.
This will cause interruptions in the sound and change the
recorded signal.
Mi PROTECTION CIRCUITRY
The protection circuitry may have operated if either of the following conditions is noticed:
@ No sound is heard when the power is switched ON.
e Sound stops during a performance.
The
function
of
this
circuitry
is
to
prevent
circuitry
damage
if,
for
example,
the
positive
and
negative
speaker
connection
wires
are
‘“‘shorted’’
,
or
if
speaker
systems
with
an
impedance
less
than
the
indicated
rated
impedance
of
this
unit
are
used.
If this occurs, follow the procedure outlined below:
1. Switch OFF the power.
2. Determine the cause of the problem and correct it.
3. Switch ON the power once again.
Note:
When
the
protection
circuitry
functions,
the
unit
will
not
operate
unless
the
power
is
first
switched
OFF
and
then
ON
again.
li BEFORE REPAIR AND ADJUSTMENT
(1) Turn off the power supply. Using a 102, 5W resistor, shortcircuit both ends of power supply capacitors (C503, C504,
6800uF) in order to discharge the voltage. ;
(2) Before turning the power supply on, after completion of repair, slowly apply the primary voltage by using a power
supply voltage controller to make sure that the consumed current at 50/60 Hz in NO SIGNAL mode should be shown
below with respect to supply voltage 110V/127V/220V/240V.
Power supply voltage AC110V AC127V AC220V AC240V
Consumed
current
50/60Hz
|
260~
380mA
|
230~350mA
|
110~230mA
|
80~200mA