Sharp 27DV-S100 Service Manual page 31

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 RECORD/PLAYBACK
MODE
• Remove the cassette housing control assembly.
• After short-circuiting R7057 and JUMPER:420
provided on the main PWB, plug in the power cord.
• Turn off the power switch. (The mechanism moves
to the cassette mounting position.)
• Open the cassette torque meter lid, and fix it with
tape.
• Load the cassette torque meter into the unit.
• Put the weight (500g) on the cassette torque meter.
• Turn on the power switch.
• Press the picture record button, and set EP picture
record mode (x3).
Set value EP6.9 ± 2.5mN·m (70 ± 25gf·cm)
Cassette torque meter
Figure 1-10.
• Checking
1. Make sure that value is within the setting 6.9 ± 2.5mN·m
(70 ± 25gf·cm).
2. The winding-up torque fluctuates due to variation of
rotation torque of limiter pulley ass'y. Read the center
value of fluctuation as setting.
3. Set the EP record mode (x3) and make sure that the
winding-up torque is within setting.
• Adjustment
If the playback winding-up torque is not within the setting,
replace the limiter pulley assembly.
Note:
When the torque cassette is set, put a weight (500g) to
prevent rise.
When the cassette torque meter is taken out.
Turn off the power switch.
• Problems caused by maladjustments
1. Much maladjusted : Tapes may get scratched.
2. Slightly maladjusted : Tapes may get slack halfway,
resulting in the STOP mode.
: Tapes may get entangled.
500g
CHECKING AND ADJUSTMENT OF TAKE-
UP TORQUE IN VIDEO SEARCH REWIND
MODE
• Remove the cassette housing control assembly.
• After short-circuiting R7057 and JUMPER:420
provided on the main PWB, plug in the power cord,
then turn on the power.
• Setting
Press the playback button and rewind button to set the
video search rewinding mode.
• Checking
Place the torque gauge on the supply reel disk, and turn
it counterclockwise very slowly (one rotation every 1 to 2
seconds) and check that the torque is within the set value
14.0 ± 3.9mN⋅m. (144 ± 40gf⋅cm)
Torque gauge
CCW
Figure 1-11.
Note:
Surely put the torque gauge on the reel disk to measure.
If the torque gauge is raised, accurate measurement is
impossible.
• Adjustment
If the rewinding playback winding-up torque is not within
the setting, replace the limiter pulley assembly.
Note:
The winding-up torque fluctuates due to variation of
rotation torque of supply reel disk. Read the center value
of fluctuation as setting.
• Problems caused by maladjustments
1. Much maladjusted : Tapes may get scratched.
2. Slightly maladjusted : Tapes may get slack halfway,
31
27DV-S100
27DV-CS10
Supply reel disk
resulting in the STOP mode.
: Images onscreen may get distorted.
: Tapes may get entangled.
: Tapes may became out from
cassette.