Realistic STA-7 - Circuit Operation Check; Power Supply Operation Check; Audio Section Operation Check

START
CONNECTION
4.
CIRCUIT
OPERATION
CHECK
1)POWER SUPPLY OPERATION
CHECK
Connect
AC
Cord to 120
V AC,
60
Hz
(UL,
C.S.A.l
(24O
V
AC, 50
Hz for Australian)
Check the
Power
Supply
voltages.
(Figure
1)
Check
the
Power
Supply circuits, Fuse
and
Power
Transformer.
DC
voltages
are
not
correct.
DC voltages
are correct.
Proceed
to next section.
2)AUDIO
SECTION OPERATION
CHECK
(1)
MAIN
AMP. OPERATION CHECK
Connect
8
O Load
to Speaker Output.
Connect DC Voltmeters
to
Pin No.
3
of
MAIN
lC 401
(lC4O2)
and
ground
(Plus
Supply)
and
Pin
No.
10 and
ground
(Minus
Supply).
See Figure
2.
MAIN AMP EOARD DC VOLTMETER
Figure
2
Check
Power
Supply
Voltage
with No lnput
(must
be
r21.2V).
Check D501-504,
C505,
506.
Check for
short-circuits.
DC Voltage
is not
i
21.2 V
.
DC Voltage
is
r21.2Y.
9.7V
ltto a 6
CONNECTION
REPAI R
-8-