Sharp 37VT-26H Service Manual page 28

37VT-26H(GY)
10. CHECKING THE VIDEO SEARCH
REWIND BACK TENSION
• Remove the cassette housing control assembly.
• After short-circuiting TP7701 (J930) and TP7702
(J359) provided at the left on the main PWB, plug
in the power cord, then turn on the power.
• 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 3.4±1.5mN⋅m (35±15gf⋅cm).
Torque gauge
CCW
Note:
Set the torque gauge securely on the take-up reel disk.
If it is not secure, the measurement will be incorrect.
11. CHECKING THE PINCH ROLLER
PRESSURE
• Remove the cassette housing control assembly.
• After short-circuiting TP7701 (J930) and TP7702
(J359) provided at the left on the main PWB, plug
in the power cord, then turn on the power.
• Checking
1. Press the play button to set the playback mode.
Take-up reel disk
Figure 1-12.
Pinch roller
Capstan shaft
Figure 1-13.
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 cap-
stan shaft.
4. Make sure that the measured value is within setting
8.8 to 11.8 N (900 to 1,200gf).
12. CHECKING AND ADJUSTMENT OF
TENSION POLE POSITION
• Remove the cassette housing control assembly.
• After short-circuiting TP7701 (J930) and TP7702
(J359) provided at the left on the main PWB, plug
in the power cord.
• Setting
1. Turn off the power switch.
2. Open the cassette tape (E-180), 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 E-180
tape.
Weight to prevent
float (500g)
Figure 1-14.
28
Tension gauge
8.8 –11.8N
(900 ~ 1,200gf)
Tension gauge adapter
(E-180)
500g