Sharp VT-G14 Service Manual page 31

Note:
Whenever replacing the reel disk, perform the height
checking and adjustment.
Master plane
Reel disk
10 ± 0.2mm
Figure 1-7.
CHECKING AND ADJUSTMENT OF TAKE-UP
TORQUE IN FAST FORWARD MODE
• Remove the cassette housing control assembly.
• After short-circuiting TP7701 (J301) and TP7702
(J302) provided at the left on the main PWB, plug
in the power cord, then turn on the power.
• Setting
1. Set a torque gauge to zero on the scale. Place it on
the take-up reel disk.
2. Press the FF button.
3. To calculate the remaining capacity of the play back
mode, slowly rotate the supply reel disk, and then
shift it into the forward mode.
• Checking
1. Turn the torque gauge slowly (one rotation every 2 to
3 seconds) by hand in the CW direction.
2. Make sure that the indication of torque gauge is not
less than 30mN·m (306gf·cm).
Torque gauge
30mN·m (306gf·cm)
or more
Idler ass'y
Figure 1-8.
• Adjustment
1. If the FF winding-up torque is less than the specified
value, clean the capstan D.D. motor pulley, reel belt,
and limiter pulley with cleaning liquid, and check
again.
2. If the torque is less that the set value, replace the reel
belt.
Reel disk height
adjusting jig
Mechanism chassis
A
B
Reel disk
CW
The gauge is held at
its maximum value.
(Red mark)
Notes:
1. Hold the torque gauge by hand so that it is not moved.
2. Do not keep the reel disk in lock state. Do not allow
long-time measurement.
CHECKING AND ADJUSTMENT OF TAKE-UP
TORQUE IN REWIND MODE
• Remove the cassette housing control assembly.
• After short-circuiting TP7701 (J301) and TP7702
(J302) provided at the left on the main PWB, plug
in the power cord, then turn on the power.
• Setting
1. Set a torque gauge to zero on the scale. Place it on
the supply reel disk.
2. Press the rewind button.
3. To calculate the remaining capacity, slowly rotate the
take-up reel disk, and then shift it into the rewind
mode.
• Checking
1. Turn the torque gauge slowly (one rotation every 2 to
3 seconds) by hand in the CCW direction.
2. Make sure that the indication of torque gauge is not
less than 30mN·m (306gf·cm).
Torque gauge
CCW
• Adjustment
1. If the rewind winding-up torque is less than the
specified value, clean the capstan D.D. motor pulley,
drive belt, and limiter pulley with cleaning liquid,
rewind again, and check the winding-up torque.
2. If the winding-up torque is still out of range, replace
the drive belt.
Notes:
1. Hold the torque gauge by hand so that it is not moved.
2. Do not keep the reel disk in lock state. Do not allow
long-time measurement.
31
VT-G14
VT-G21
30mN·m (306gf·cm)
or more
The gauge is held at
its maximum value.
(Red mark)
Supply reel disk
Idler ass'y
Figure 1-9.