Technics SU-Z65 - Before Repair and Adjustment; Pre-Repair Safety Precautions

Equalizer circuit
Power transistors
Cm: mem Protection circuit
ee Impedance
i} detection circuit
FL. peak power level meter circuit
Volume contro! circuit
L ch, voltage amplifier circuit R ch. voltage amplifier circuit
M@
BEFORE
REPAIR
AND
ADJUSTMENT
Turn
off
the
power
supply
and
short-circuit
both
ends
of
power
supply
condensers
(C501,
502,
6800uF)
at
resistance
(about
10,
5W)
in
order
to
discharge
the
charged
voltage.
Avoid
short-circuit
with
a
screwdriver
or
the
like,
otherwise
the
transistors
or
diodes
may
break
down.
Before
turning
on
the
power
supply
after
completion
of
repair,
slowly
apply
the
primary
voltage
by
using
a
voltage
regulator
to
make
sure
that
the
current
consumed
is
free
of
abnormality.
The
current
consumed
at
60Hz/50Hz
in
no-
signal mode is shown below with respect to supply voltage 110V/120V/220V/240V. :
Power supply voltage AC 110V AC 120V AC 220V AC 240V
220 ~ 440mA 200 ~ 400mA 110 ~ 220mA 100 ~ 200mA
Current consumed
200 ~ 400mA 180 ~ 360mA 100 ~ 200mA 90 ~ 180mA
e
Caution
Thermistor
* When the power transformer
hasbeen
replaced,
attach
the
thermistor
(100kQ)
to
the
RR
i
Ste
=>
cover
of
power
transformer
—
by
using
the
thermistor
White
Thermistor
retainer,
and
secure
it
with
Tube(@)
Tube®)
°
adhesive.
;
Fig.
1
Fig.
2
*
How
to
fix
the
thermistor.
.
The
thermistor
is
covered
Bg
gana
With
insulating
tube,
as
Thermistor
retainer
illustrated,
to
prevent
shortcircuit.
Secure with adhesive
Fig. 3 Fig. 4