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PL-3000
e Includes motor dead point
e Rotate Motor by hand.
Do the voltages between each of the Hall
element outputs (pins 11 and 12, 13 and
14, and 15 and 16 of PA3006) register
at least 0.2V ?
And are all the DC levels at least 9V ?
Defective Hall element.
Turn
the
power
off, and measure
the
resistance between Vcc and pins 18, 19,
and
20
of PA3006.
(connecting
the
positive probe of the multimeter to Vcc).
Is a reading of 602
+ 40
obtained in
each case ?
Does 0.8V register between pin no.17 of
PA3006 and ground ?
Defective PA3006 ?
Infinite resistance: break in coil
Resistance too low: shorted coil
4.2 CONSIDERABLE WOW AND FLUTTER IN MOTOR
Check the Hall element operation (see@
Turn the power on, and rotate the turn-
above under "Motor Fails to Rotate'').
table platter slowly (about 1 rotation in
5 seconds). Do the voltages at pins 18,
19, and 20 of PA3006 switch back and
forth between 18V and 1V ?
Check
the coil (see @ and @ above
under the same ''Motor Fails to Rotate"
section).
YES
Defective diode.
Even if only 1 diode is defective, all 3
must be replaced as a single set.
Remove
D;,
D,,
and
D;,
and
check
them
for
normal
conduction
with
the
multimeter).
YES
When measuring with a wow and flutter meter,
1 deflection per revolution indicates a lack of mechanical alignment, or defective shaft
or shaft bearing,
1 deflection per 2 revolutions indicates a defective shaft or shaft bearing,
while 4 deflections per revolution indicate defective capacitors (C; ~~ C,) or PA3006.
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