Sharp VC-384N Serviceanleitung Seite 11

e Adjustment
1) If the distance between the tension pole and SI roller,
measured at their centers, is smaller than 0.5mm,
move tension band adiusting angle (1) in the direc-
tion of B (See Figure 14) then tighten screw (2).
2) If the distance between the tension pole and SI roller,
measured at their centers, is greater than 1.0mm,
move tension band adjusting angle (1) in the direc-
tion of A (see Figure 14) then tighten screw (2).
Precaution:
1. Be sure to apply locking paint to the screw after
adjustment.
2. Do not tighten the screw excessively: otherwise
threads cut in the chassis would break.
CHECK AND ADJUSTMENT OF TENSION
POLE VERTICALITY
@ Checking Procedure
1) Remove the cassette housing and hold the cassette
down switch PVC tape.
2) Install the fixed guide height adjusting jib as shown in
Figure 15.
3) Check veticality of the tension pole is perpendicular
(90°) to the main chasis.
Parallel :
Fixed guide height Tension pole
adjusting ji | f
9 jig
' | :
Main chassis A
Figure 15.
CHECK AND ADJUSTMENT OF BACK TENSION
DURING RECORD AND PLAYBACK
@ Checking Procedure
With the back tension test cassette
1) Remove the cassette housing and hold the cassette
down switch with PVC tape.
2) Load the back tension test cassette tape.
3) Depress the play button. Check that back tension is
50 — 57g-cm in play mode (look at the needle of the
back tension test tape).
4) Check that the video tape is running around the fixed
guide.
5) Check that the tape is tight and edges are not
damaged at the beginning and end of tape.
Figure 16.
11
@ Adjustment
1) If the tape tension is weak (smaller than 50 — 57g-
cm), move the hook of the spring toward A (see
Figure 16) and check tape tension again.
2) If the tape tension is strong (smaller than 50 — 57g-
cm), move the hook of the spring toward B (see
Figure 16) and check tape tension again.
3) When the hook of the spring has been moved, fasten
it with bonding agent.
CHECKING PROCEDURE OF REEL BRAKE TORQUE
1. Checking prodedure of supply side medium brake
Precaution:
1. Check medium brake earlier than strong brake.
2. Make measurement within 10 seconds after plugging
the power cord and remove the shorting.
3. Check supply side medium brake torque with rota-
tion of both clockwise and counterclockwise direc-
tions.
4. Supply side medium brake torque should be more
than 100g-cm which is less than half of take-up side
strong brake.
@ Checking Procedure
1) Remove the cassette housing.
2) Unplug the power cord and short the R803 side of
R801 mounted on the system control board to the
ground.
3) Separate the reel idler from the supply reel disk and
install a torque gauge.
4) Plug the power cord.
5) Turning the torque gauge slowly (at a speed of a turn
for every 2-3 seconds), check that supply side
medium brake torque is more than 100g-cm.
Torque gauge
; Reel pulley
Reel idler Supply reel disk
Torque gauge
head
Supply reel disk
Z.
Figure 17.
2. Checking procedure of take-up side medium brake
Precaution:
1. Check medium brake earlier than strong brake.
2. Make measurement within 10 seconds after plugging
the power cord and remove the shorting.
3. Check take-up side medium brake torque with
rotation of both clockwise and counterclockwise
directions.
4. Supply side medium brake torque should be more
than 100g-cm which is less than half of supply side
strong brake.