Sony DNW-A75 Maintenance Manual page 110

4-2. TAPE Maintenance Mode (M0)
4-2-2. SERVO CHECK Mode (C00-03)
C012 : THREADING MOTOR
This submenu checks the functions of a threading motor, threading end sensor, and
unthreading end sensor.
Checking
(1) Turn the search dial (in JOG mode) slowly continuously in FORWARD (2)
direction.
. Check to see that a threading ring rotates counterclockwise (3) and that a
message on the superimposed display changes from "UNTHREAD END" to
"...........".
. Check to see that the threading ring stops in the threading end state and that
the message changes from "..........." to "THREAD END".
n
When the search dial pauses halfway, the threading ring also stops.
(2) Turn the search dial (in JOG mode) slowly continuously in REVERSE (3)
direction.
. Check to see that the threading ring rotates clockwise (2) and that the mes-
sage changes from "THREAD END" to "...........".
. Check to see that the threading ring stops in the unthreading end state and that
the message changes from "..........." to "UNTHREAD END".
n
When the search dial pauses halfway, the threading ring also stops.
(3) To finish the check, press the MENU button once in the unthreading end state.
n
Unless the unthreading end state, a massage "SET UNTHREAD END TO
RETURN" will be displayed on pressing the MENU button.
In case of NG
. Check the mechanical abnormality.
. Check the threading motor driver circuit on the DR-315 board.
. Check the threading motor.
. Check the threading end sensor or unthreading end sensor on the TR-79 board.
. Check the sensor input port of MPU (IC1 on the MS-58 board).
Threading motor
4-20
Locations of Threading End and Unthreading End Sensors
SERVO CHECK
MOTOR CHECK
C012:THREADING MOTOR
* * * * * *
UNTHREAD END
TURN JOG DIAL
IN JOG MODE
FWD:THREAD, REV:UNTH
DIAL
DIAL
(2) (3)
SERVO CHECK
MOTOR CHECK
C012:THREADING MOTOR
...........
TURN JOG DIAL
IN JOG MODE
FWD:THREAD, REV:UNTH
DIAL
DIAL
(2)
(3)
SERVO CHECK
MOTOR CHECK
C012:THREADING MOTOR
* * * * * *
THREAD END
TURN JOG DIAL
IN JOG MODE
FWD:THREAD, REV:UNTH
SERVO CHECK
MOTOR CHECK
C012:THREADING MOTOR
* * * * * *
THREAD END
# SET UNTHREAD END #
# TO RETURN #
TURN JOG DIAL
IN JOG MODE
FWD:THREAD, REV:UNTH
Unthreading end sensor
Threading end sensor
Threading ring
(Unthreading end state)
DNW-A75/A75P