Technics ST-HD50 - Power Supply for Servicing; Signal Output Check

ST-HD50 |
mi To Supply Power Source
This unit ST-HD50 is designed to operate on power supplied from the Amplifier SE-HD50.
When operating the unit ST-HD50 alone for testing and servicing, without having power supplied from the
Amplifier SE-HD50, use the following method.
Power Supply to Main Circuit
1. Short the section between the test points Bits ((CT]) andiim:aie} (|D.GND}), and as well as the section between the test
points (J601) and ([D.GND)).
2.
Connect
the
10
V
AC
power
through
the
capacitor
(35V
100uF)
to
pin
1
of
the
indicator
module
FL901
and
the
GND
terminal
through
the
capacitor
(35V 100uF)
to
pin
57
of
the
same
FL901 module.
3. Apply 10 V AC power to the section between the point [ifn ((AC]) and the point [iad ((CT)) as well as the section
between the point [uGgsee] ([AC]) and the point [fae ((CT]). This unit comes to stand-by mode.
4. Short the section between the jumper (JK603-pin 9) and the point fiz) ([D.GND)) fora moment. The main circuit
comes to power ON mode. (Whenever this operation is performed, power, ON/OFF mode is repeated.)
To Check Signals
Connect
the
oscilloscope
or
the
speaker
with
the
built-in
amplifier
to
the
section
between
the
point
J626
[
LINE
OUT
(R-ch)
]
and
the
point
fisdsaK4
(|D.GND))
as
well
as
the
section
between
the
point
J627
[
LINE
OUT
(L-ch)
]
and
the
point
uis#f¢]
((D.GND
)
as
shown in Fig. 1, and check if the signals are outputting from this unit.
(T.GND)
(pin9)
(AC
Power
Supply)
i:]'
A.GND
|i
+
ee oe
J604
J601
i (Ac}) i
602 {{ #:)
biz) (C7);
osorfs)
bizare (AC)
(Tuner P.C.B.)
When short this point for a
moment, comes to power" ON ".
J313—0—
LINE OUT (R-ch) J626 fastens) ([D.GND))
7
LINE OUT (L-ch) +++—— Je2
Note: This unit ST-HD50 don't have
any adjustment points.
Fig. 1