Sharp VC-MH80 Service Manual page 17

CHECKING THE FAST FORWARD BACK
TENSION
l Remove the cassette housing control assembly.
l Make a short-circuit between TPSOOI a n d ,
TP5002, both located on the timer PWB. Now'
turn on the power.
l Checking
1. Push the FF button to place the ass' y in the
fast forward mode.
2. Place the torque gauge on the supply reel
disk, and turn it clockwise very slowly (one ro-
tation every 2 to 3 seconds) and check that the
torque is 1.5 + 0.9mN.m (15 f: 9gfcm).
disk. If the torque gauge is not securely set on
the reel disk, measurement will be incorrect.
@Measure the torque with the torque gauge' s
weight exerted on the reel disk.
CHECKING THE REWIND BACKTENSION
Remove the cassette housing control assembly.
Make a short-circuit between TPSOOI a n d
TP5002, both located on the timer PWB. Now
turn on the power.
Checking
1. Push the REW buton to place Place the ass' y in
the 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 1.3 + 0.8 mN-m (13 +
Torque gauge
Take-up reel disk, u
Note:
reel disk. If it is not secure, the measurement will
be incorrect.
weight exerted on the reel disk.
CHECKING THE VIDEO SEARCH REWIND
BACK TENSION
Remove the cassette housing control assembly.
l
Make a short-circuit between TP5001 a n d
TP5002, both located on the timer PWB. Now
turn on the power.
Checking
1. Push the PLAY button to place the ass' y in the
playback mode.
2. Push the rewind button to place the ass' y in the
video search rewind mode.
3. Place the torque gauge on the take-up reel disk,
and turn it counterclockwise very slowly (one ro-
tation every 2 to 3 seconds) and check that the
torque is within the set value 4 f 1.7mN.m
(41 + 17gfcm).
Torque gauge.
Take-up reel disk
Note:
reel disk. If it is not secure, the measurement will
be incorrect.
@Measure the torque with the torque gauge' s
weight not exerted on the reel disk.
CHECKING THE PINCH ROLLER PRESSURE
l Remove the cassette housing control assembly.
l
Make a short-circuit between TPSOOI and
TP5002, both located on the timer PWB. Now
turn on the power.
l Checking
Push the PLAY button to place the ass' y in the
playback mode.
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