Sony TC-458 - Troubleshooting; PAUSE Mode

TROUBLESHOOTING
No motor rotation
Too fast speed in
forward and reverse
modes
No or too slow fast
forward and rewind
Tape run away in
PAUSE mode
Tape scraping on reel
flanges
Electrostatic noise
No recording and no
playback, or recording
and playback during
ferrite head unit
rotation
No auto shut-off
(3, 4, 7 and 8) of RY601
Defective servo control power switch Clean contacts or replace switch.
(S802)
SECTION 3
ADJUSTMENTS
Possible Cause
Incorrect position of motor switch Readjust motor switch position.
(S906)
Defective motor switch (S906) Replace motor switch.
Defective servo amp or defective Q901 Check servo amp complete circuit
board or Q901.
Replace motor or clean contacts of
RY601, or replace RY601.
Defective motor or defective contacts
Incorrect operation of servo release Check S803 and servo amp circuit.
switch S803 or run away of servo amp
Incorrect rewind and fast forward Readjust rewind and fast forward
torque adjustment torque.
Incorrect clutch release lever : Readjust clutch release lever position.
adjustment
Servo amp circuit is connected to the Check and replace switch.
motor due to incorrect operation of
servo control release switch S803
Supply-side tension regulator is not Readjust tension regulator back
released tension and check solenoid PM903.
Readjust take-up torque.
Too much forward and reverse torque
Incorrect pause lever (B) ass’y position Perform pause lever adjustment (1).
Incorrect pause lever (B) position Perform pause lever adjustment (2).
Use new reel. ;
Bent or damaged flanges
Incorrect height of tape path Check and perform tension arm cap
adjustment.
Incorrect discharger position Check and readjust discharger position.
Apply antistatic liquid to drive-belt
surface.
Electrostatically charged drive belt
Check $904, D619, Q403, Q503 and
associated muting.circuit components.
Faulty muting circuit
Unreleased head rotating solenoid Check and replace detector switches
PM901 $901 and $902, Q603 and/or Q604.
Incorrect actuator rod position Check and readjust position.
Incorrect position of shut-off solenoid Check and readjust position.
PM902
Defective transistor Q603 and/or Q604 Check and replace Q603 and/or Q604.