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11.. Trouble Shooting
Electrical Circuit
1. Playback tone quality is poor.
1) Check the record/playback head for dust.
2) Check the record/playback head for wear.
If worn excessively, the loss of treble response will result.
3) Check wiring for a short-circuit.
Check each transistor for condition.
(Check voltage according to
the circuit board parts diagram.)
4) Check the noise reducing circuit for condition.
(This check-up should be made by turning on and off
the switch of the ANRS.)
2. Recording tone quality is poor.
The playback tone quality of a recorded tape such as the audition tape is good, but the recording by this
unit produces poor tone quality.
In this case, the unit should be checked in the following manner.
1) By monitoring a music while recording, check the tone quality.
2) If found poor, check the wiring of the recording system for a broken wire and short-circuit.
Check
transistors for function by measuring voltage.
3)
If no irregularity is found, check the recording bias current according to 6—3 above.
Also check the
oscillation circuit.
4)
Check the noise reducing circuit for operation.
3. For other failures, check the unit in the same manner as other amplifiers.
Mechanism Section
As for the torque and pressure of rollers, details are given in "Mechanism Adjustment" on page 00, and
therefore, this section refers to the adjustement of wow and flutter.
Adjustments:
If wow and flutter increase, check the following points.
sound.
Capstans
Pinch rollers
Capstan shaft has excessive
run-out.
Flywheel turns heavily
(Shaft seisure, thrust play, etc)
Rough rotation (Deformation,
scratches, or dust)
Angle is incorrect.
Pressure is incorrect.
Replace flywheel.
Adjust flywheel holder.
Replace pinch roller.
Clean.
Adjust so that it is parallel to capstan.
Adjust spring.
Take-up belt
Belt has undue run-out.
Belt is dirty or slipery.
Replace take-up belt.
Clean or replace.
Back tension
Motor
_|
Back tension is irregular, or
back tension is too strong.
Replace supply disc.
Replace back tension
spring (under
supply disc), or apply silicon grease.
Motor shaft has undue run-out.
Motor pulley is oily and dusty.
Take-up idler arm
CD-1667, 1667U
Replace motor.
Clean motor pulley.
Pulley has deflection.
Pulley is stuck.
_—18—
Replace take-up idler arm.
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