Sharp VC-780E

V -fOVE
VC-790ET
Note: :
-The measured torque fluctuates due to the
rotational deviation of the reel drive unit. Use
the center of the fluctuating range as the
measured value.
1. If the take-up torque in playback mode ts outside
the specified value, replace the take-up reel disk.
2. Push the record button to place the unit in the
record mode, and check that the take-up torque
‘is within the specified range.
CHECKING OF TAKE-UP TORQUE IN VIDEO »
SEARCH REWIND MODE —
@ Checking
Load a cassette torque meter UiGVHT-063) into
the unit and push the play and video search
rewind buttons to place unit in the video search
rewind mode.
Then check that the torque is as specified;
torque in video search rewind mode : 170 +
40 g.cm
Note:
The measured torque fluctuates due to the
rotational deviation of the supply reel disk. Use
the center of the fluctuating range as the
measured value.
1. If the take-up torque in video search rewind
mode is outside the specified range, replace the
supply reel disk.
CHECKING THE FAST FORWARD BACK
TENSION
Note:
Set the torque gauge securely on the supply reel
disk; if the torque gauge is loose above the reel
disk, an inaccurate measurement wil! result.
@ Checking
. Remove the cassette housing assembly.
. Push the fast forward button to place the unit in
the fast forward mode.
3. Place the torque gauge on the supply reel disk,
and turn it clockwise very slowly (one rotation
every 2 to 3 seconds) and check that the torque is
within 15+ 5 g.cm.
AJ os
Supply reel disk
Torque gauge
Torque gauge
head
Supply reel disk
Reel pulley Idler gear
{center gear}
CIA TI Le PLTTALITL
{b) side view
(a) top view
Figure 1-12.
14
CHECKING THE REWIND BACK TENSION
Note:
Set the torque gauge securely on the take-up
reel disk; if the torque gauge is loose above the
reel disk, an inaccurate measurement will result.
® Checking .
. Remove the cassette housing assembly.
. Push the rewind button to place the unit in the
rewind mode. ‘
3. 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 15+ 5 g.cm.
No —
CHECKING THE VIDEO SEARCH REWIND
BACK TENSION
Note:
Set the torque gauge securely on the take-up
reel disk; if the torque gauge is loose above. the
reel disk, an inaccurate measurement will result.
@ Checking
1. Remove the cassette housing assembly.
2. Push the play button to place the unit in the
playback mode.
3. Push the video search rewind button to place the
unit in the video search rewind mode.
4. 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 40 + 10 g.cm.
CHECKING THE PINCH ROLLER PRESSURE
1. Remove the cassette housing assembly.
2. Push the play button to place the unit in the
playback mode.
3. Hook the tension gauge adapter srdund the
pinch roller shaft.
4. Using a tension gauge, pull the pinch rofler‘in ati
direction of arrow = @ so that the pinch roller
moves away from the capstan shaft.
5. Gradually release the pressure in the diréétion of
arrow ©) to allow the pinch roller to touch the
capstan shaft. When the pinch roller just touches
the capstan shaft, read the indication on the
gauge.
6. Check that the reading of the tension gauge isin
the range of 1000 to 1200 gr.