Technics SA-GX230 Service Manual

SA-GX230-
Ш
MEASUREMENTS
AND
ADJUSTMENTS
Note:
For
2201/2251
(AM
(MW/LW)
ANT
and
OSC
coil),
7202
(AM
(MWILWMIFT),
they
are
supplied
as
adjusted
parts.
|
So,
do
not
turn
the
cores
of
the
parts.
Н
is
not
necessary
to
adjust
the
AM
(MW/LW)
circuit.
* FM ADJUSTMENT
Control
positions
and
equipment
used
*
FM
signal
generator
(FM-SG).
*
Frequency
counter
*
Distortion
analyser
•
Choke
coil
(100pH)
*
DC
electronic
voltmeter
(DC
EVM)
*
Resistor
(100
kQ)
. Remove the motor cover by used © screwdriver.
(Refer to Fig. 3)
4. Remove the motor from, the fancasing.
Ref.
No.
Removal
of
the
power
supply
P.C.B.
ner
NO;
Removal
of
the
power
transformer
ner
No:
Removal
of
the
cooling
fan
motor
11
12
(main)
16
Procedure
Procedure
Procedure
o
12911
1911412
1->9->16
(Refer
to
Fig.
4)
5.
When
mounting
the
motor
fan,
align
the
fan
1.
Release the 3 claws in the direction of arrow and casing’s projection with the hole of.the fan motor.
remove the fan motor. (Refer to Fig. 1) |
2. Insert a screwdriver at the root of the cooling fan.
Force it out of the motor shaft. (Refer to Fig. 2)
transformer Cooling" fari
(main)
FM
MONO
DISTORTION
ADJUSTMENT
FM
SIGNAL
GENERATOR
CONDITION
.
Test
equipment
connection
is
shown
in
figure.
Modulation
. Set the unit to “FM” position.
.
Set
the
radio
frequency
display
and
signal
generator
to
100.10
MHz.
|
| |
о
T
.
Adjust
Т201
core
so
that
voltage
measured
in
signal
mode
is
OmV
(0+20mV)
in
300mV
range.
.
Adjust
T202
so
that
the
distortion
factor
of
Lch
is
minimized.
.
.
EM
ET
.
Repeat
step
4
and
5a
few
times.
—
.
Make
sure
that
the
distortion
factors
of
Lch
and
Rch
are
nearly
the
same
with
each
other to
minimum.
Power, supply PC. B.
1. Remove the 1 screw (@). |
2. Remove the 1 flat cable (CN702).
3, Remove the power supply P.C.B. in the direction of
arrow. 2 Ұй
|
Қай
Removal
of
the
regulator
transistor
|
Procedure
1-2-13
Remove the 2 screws (Ф, Ө).
Remove the 2 transistor holders.
Lift up the connector in the direction of arrow (D.
Remove the regulator transistor in the direction of
arrow ©).
Note:
Ref
№.
|
Check
of
the
main
P.C.B.
Procedure
|
swhen
checking
the
soldered
sur-
1—17
faces
of
main
P.C.B.
and
replacing
—
.
о
o
the
parts,
do
as
show.
X
f
Front
panei
аѕѕ?у
The
adjusting
screwdriver
used.
should
be
made
of
resin.
|
|
|
емей ай =
FM
MPX
VCO
ADJUSTMENT
FM
SIGNAL
GENERATOR
CONDITION
. Test equipment connection is shown in figure. Modulation
.
Set
the
unit
to
"FM
auto"
position.
|
.
Set
the
radio
frequency
display
and
signal
generator
ÉREGUENEY
to
100.10
MHz.
QU
ENNA
COUNTER
.
Adjust
VR301
for
19.00+0.03kHz
on
frequency
counter
reading.
—
.
>
3
i
па й
зі
: | X USING ALTERNATE SYSTEM
1.
Apply
stereo
signa!
from
generator
or
receive
the
stereo
broadcast.
|
2.
Adjust
VR301
until
stereo
indicator
lights
up.
%
-
®
—
©
:
Stereo
OFF
Cement
arm
of
VR301
as
shown
in
figure.
* When mounting the regulator transistor.
Apply
silicone
thermal
compound
(RFKX0002
or
equivalent)
to
the
rear
of
the
regulator
transistor.
Removal
of
the
main
P.C.B.
LET
Removal
of
the
power
IC
|
Procedure
Procedure
125259
152—910
position
- © : Stereo ON positlon
|
(indicator
lighting)
|
©: Adjust point of Pilot circult
1. Remove the 3 screws (Ф--Ө).
Rear panel
*
Adjustment
points
a.
а
Please
refer
to
tuner
P.C.B.
on
pages
27,
28.
TH
Teel
a
UEM
SD
SM
GNO E
44%
Y
—
[—— 750.
Unsolder
the
power
IC
FM
ANT
?
"
‚
1.
Remove
the
2
screws
(Ф,
Ө):
|
@
‚2.
Unsolder
the
power
IC.
BALANCED
TUNER
P.C.B.
Front panel ass!y
¢ When mounting the power IC.
1.
Remove
the
1
flat
cable
(CN702).
^A
Apply
silicone
thermal
compound
.
(RFKX0002
ог
2.
Remove
the
6
screws
(Q
—
OQ).
|
equivalent)
to
the
rear
of
the
power
IC.
3.
Remove
the
6
screws
(D—().
—
5.
Remove
the'chassis
ass’y.
4.
Remove
the
rear
panel
іп
the
direction
of
arrow..
6.
Reinstall
the
front
panel
ass’y
to
the
main
P.C.B.
FM offset! FM МОНО
coll OISTORTION сон
—Hh-
|
—12—
|
ue
n
—
13—
[129]
[1202]
d
|
|
|
‚
|
T
|
i
'
|
|
!
|

Technics SA-GX230 Specifications

General

Brand	Technics
Model	SA-GX230
Category	Stereo Receiver
Language	English