JVC QL-F6

(2) Platter rotates at high speed.
Platter rotates at high speed.
Rotates at high speed
when the start button is depressed.
Does connecting the
base of X16 to +24 V
stop rotation?
When the terminals
of R30
, R31
, R32 are
grounded
, does rotation
stop?
X 16 is defective.
Replace.
QL-
No. 2464
Yes
I s rectangular
waveform present at
Pin 7 of IC4?
Yes
X17 is defective.
Replace.
Yes
Check the Schmitt cir- cuit and AC
amplifier
sections
, and the FG
output of motor.
Fig. 25
Is the waveform
shown in the circuit
diagram present at
Pin 4 of IC1?
Yes
Check if C22
, R6
, R68
are disconnected.
Replace if they are.
Yes
Check if
IC1 is defec-
tive
, R67 is disconnect-
, VR4 is open.
Replace if necessary.
Note: Don t disconnect the motor from
electronic
circuits while troubleshooting as this
may
damage the transistors in the drive circuit.
13 -
IC5 is defective. Replace.