JVC L-A31

The turntable rotates at high speed.
Does the
turntad'e stop
when TP-3 (the base of
X12) is connected to
END
Deactivate the drive circuit
Yes by connecting the base of
X11 to the +18.6 V line,
then...
A short-circuit is being
made between the col-
lector and emitter of
X12, of some other cause.
turntas e@ stop
when the sase of X11 is
conne=zed to the
18.€ V line?
A short-circuit is being
made between the col-
lector and emitter of X11,
or some other cause.
Does the
turntazie stop
when the co.:ector of X11
is connected to
GNO?
1
\
1
The connect:on pattern of -
R11 and R12 touches the ;
+18.6 V line.
L-A31 .
No. 2555
rotating the turntable
at around 33-1/3 RPM by hand, does
FG output voltage 5 mV (p-p)
apppar?
Yes
No
1
The pattern of the FAG is disconnected,
the rotor magnet flaats, or some other
cause. {
-13—
oO aRe eet
Does an
Output of around
5 Vip-p) appear at TP-1?
@: 5V(p-p)
Does the
waveform in pro-
portion to RPM ap-
pear at pin (3) of 1C1?
Its associated pattern is discon-
nected, the soldered joint of its
associated element is not per-
fect, or some other cause.
C3, C6, 1C1, or anything is
defective.
Yes
Yes.
1C1 is defective,
the capacity of
C10 is lost, R30
is disconnected,
or some other
cause.
Does a
sawtooth shapes wave
appear at pin 13 of 1C1?
Yes
2V(p-p)
1C1 is defective, the capacity of C9 or C4 is lost,
or some other cause.