Sharp DV-NC70U Service Manual page 25

8-12 CHECKING THE VIDEO SEARCH REWIND
BACK TENSION
• Remove the cassette housing control assembly.
• After short-circuiting between TP803 and TP802
provided at main PWB, plug in the power cord.
• Checking
1. After pressing the play button, press the rewind button,
and set the video search rewind mode.
2. Place the torque gauge on the take-up reel disk, and turn
it counterclockwise very slowly (one rotation every 2 to
3 seconds) and check that the torque is within the set
value 3.7 1.5mN m (38
Torque gauge
CCW
Figure 8-11.
Note:
Set the torque gauge securely on the take-up reel disk.
If it is not secure, the measurement will be incorrect.
8-13 C H E C K I N G T H E P I N C H R O L L E R
PRESSURE
* Checking can be perform with or without cassette
housing control.
• Remove the cassette housing control assembly.
• After short-circuiting between TP803 and TP802
provided at main PWB, plug in the power cord.
• Checking
Press the play button to set the playback mode.
1. Detach the pinch roller from the capstan shaft.
Do not separate excessively. Or the pinch lever and
pinch double action lever may disengage.
2. Engage the tension gauge adapter with the pinch roller
shaft, and pull in the arrow direction.
3. Gradually return the pinch roller, and measure the
pulling force when the pinch roller contacts the capstan
shaft.
4. Make sure that the measured value is within setting
change to 9.8 2N (1.0
15gf cm).
Take-up reel disk
0.2kgf).
Pinch roller
Capstan shaft
8-14 CHECKING AND ADJUSTMENT OF
TENSION POLE POSITION
* Checking can be perform with or without
cassette housing control.
• Remove the cassette housing control assembly.
• After short-circuiting between TP803 and TP802
provided at main PWB, plug in the power cord.
• Setting (without cassette housing control)
1. Turn off the power switch.
2. Open the cassette tape (T-120), and fix with tape.
3. Set the cassette tape in loading state.
4. Put the weight (500g) on the cassette tape.
5. Turn on the power switch.
6. Make the adjustment with the beginning of a T-120 tape.
• Setting (with cassette housing control)
1. Insert cassette tape (T-120)
2. Make the adjustment with the beginning of a T-120
tape.
Weight to prevent
float (500g)
25
DV-NC70U/C
DV-NC72U
Tension gauge
900 - 1,200gf
Tension gauge adapter
Figure 8-12.
(T-120)
Figure 8-13.