Technics SA-GX550 Service Manual

SA-GX550
Mi FAN MOTOR TROUBLESHOOTING GUIDE Mi TERMINAL FUNCTION OF IC
The
Models
SA-GX350/GX550/GX650
employ
fan
motor
error
sensing
electronics.
¢
1C901
(LC8A012A5328):
"7
If the cooling fan is not operation and its STANDBY light (D929) is on, check the fan motor and its STANDBY
light (D929) is on, check the fan motor and its driving circuit.
S_ IN/OUT terminal P.C.B.
Te)
pion] = ‘metlon |
cuion| = Fameon
The STANDBY RED
(0929) is lit.
a
SPB
41 DATA1
n TS
>
Is the
air cooling
Path blocked or the
fan motor jammed
by any external
obstacle?
FM
eS wo
> >
YES
Remove the obstacle,
Y
> 4 DATA2
16cm
|
Straight
NO
AFM
Muting
control
terminal
45
Level
shift
control
terminal
driver
cannot
Remove
the
fan
from
2d.) the unit.
—20dB
for)
rr
Muting control (—20dB) termina Serial clock Serial clock signal
yD
Is
the
fan
NO
Fan
motor
failure
DG1
as
, ;
motor’s
DC
resistance
Short
circuit:DC
resistance
below
5Q
Ps
Bey
Digit
signal
of
FL
display
7
Remote
control
terminat
20~302?
Open
circuit:DC
resistance
over
1kQ
YES
$13
Segment
signal
of
FL
display
Level
shift
control
terminal
Reinstall
the
fan
on
the
unit.
DD
Power
supply
terminal
49
TEST1
Test
terminal
Are the
_
s| = | =
0
re Wer sUEPl ternal onee Reset detect terminal
display
Not used, connected to power
supply
terminal
voltage
of
Q652
19
S12
;
*
and
Q653
normal
in
Yes
|
Check
the
integrity
of
Q651,
0652,
a6
at
Seament
sioneliol
Fledispley
:
both
active
and
inactive
Q653
and
the
fan
motor
driving
states of the fan
motor?
(see table 1.)
circuit. (see fig. 1.)
bs
g.2
volume motor
ope
iley- Proto Europe
»dside, Sheffield
PD
land
44-742-739-038
ne: 44-742-768- 888
Q651,652,654,655 FAN OFF: -O.lV
FAN"O
FF”:
Ov
2SAIZSO9AQSTA
FAN"ONT:
-8.2V
FANON":
~0-8V
FAN“ON":
-
0.65V
MOTOR
DRIVE
‘is
(Voltage table)
<
reste
fo) o LS)
pS
als
m
FMST
>
0651
MAI6STA
FAN‘OFEF’:-0.65V
ada FAN‘ON’: -O.IV
iley- Proto Canada
O Corporate Drive
ington, Ontario
jada, L7L 5R6
; 416-335-0075
ne: 416-335-0075
IFDAIN
a N
ee
60 KEYS
37 LOUD
(Table (1))
s e Q653
FAN‘OFF’: -14v
[FANON -tz.5Vv 2SB62IAQSTA
MOTOR ORIVE
ST3 61 | STANDBY
die East, Mediterranean agate rene Fig. 4
rica
p
resent
at
p
i
ns
®
NO
The
Power
1c
¢)
C601
or
10602)
3
2
Video
selector
control
terminal
S2
ENCODE
Not
used,
connected
to
power
ley-
MEMA
and
©
of
1C601_or
is
defective,
ENCODE
B
supply
y House The Ring
>knell Berkshire
121A2
land
| 44-344- 485-526
ne: 44-344-51813
fo.) >,
=
Chip enable terminal ee | Remote control terminal
The fan motor, Power ICs
and fan driver are
functioning normally.
—
19
—
20

Technics SA-GX550 Specifications

General

Brand	Technics
Model	SA-GX550
Category	Stereo Receiver
Language	English