Technics RS-TR474

es the voltage at Q603
lector change from OV to
V?
Q603 soldering check or
replacement.
es the voltage at Q604
lector change from —20V to
v?
Q610 and —20V system check.
28 the voltage at D613 change
m OV to 8.2V ?
D613 soldering check or
replacement.
R622 disconnection, or Q605
check or replacement. :
3 the voltage at Q605 emitter
inge from —0.4V to 7V ?
YES -
ver is normal.
RS-TR474_- RS-TR474
Power switch turns on but
mechanism does not operate
(common to both mechanism).
Voltage check:
Approx. 5V at CN1 pin 9 and CN2
pin 14
Approx. 7.5V at CN1 pin 13 and
CN2 pin 12
Approx. 15V at CN1 pin 10 and
CN2 pin 13
OV (ground) at CN1 pin 12 and
CN2 pin 10
NO
Connection and power check.
Check switches in the self-
diagnosis mode.
|
ie
Is any switch failure stored in YES Replace any failed switch with a
memory ? new one. ;
Do open/close operations work YES
properly ? j
NO
NO
DECK 1: $801, $802
DECK 2: S803, S804
Unplug the power cord and force
the door to the half-open position
by hand. ‘
When it is plugged in again,
YES | Both power; and microprocessor
check the door closes correctly system are normal.
with both door switches (S801 5
and S802) still in the off
positions.
NO '
DECK 1: $801, S802, CN1 ®
DECK 2: $803, S804, CN2 ©
Does the voltage at CN1 pin 3 NO ; ;
change when the door switch yh
($801 and $802) is forced into the suena
on position ?
YES |
DECK1:@
DECK 2:@
Does the voltage at the
microprocessor terminal also
change ?
YES
| Check connection between the
motor PCB. and the sub PCB.
To the microprocessor check ;
section.
Does the flywheel turn instantly
when the AC cord is plugged in ?
YES
Force the mode switch into the
on position for more than a
second.
Does the head lift once and then
lower ?
Does the plunger instantly pull
in?
NO
Are power and connection
checks normal ?
NO
To the microprocessor check
section.
Power failure.