Mechanism Checks And Adjustments; Reel Table Torque Check - Sony SVT-RA40 Service Manual

4. Mechanism Checks and Adjustments

4-1. Reel Table Torque Check

1. With the power switch turned OFF, stick black vinyl
tape over the photo diodes of the tape sensors. Then
turn the power switch ON. Front loading will begin.
Refer to Section 3-2 and Fig. 3-2-2, and release the
locks of the tray lock lever and the lid opener lever.
m
. The measurements must be taken without any incandes-
cent light or daylight.
. If the mechanism cannot be put into PLAY, FF or REW
mode by the method described in 1) above, make a
dummy cassette tape, as shown in Fig. 4-1-2. The
dummy cassette tape is made as follows: Unscrew the
five screws on the underside, remove the reels, leaf
springs and other parts on the supply and take up sides,
make holes in the upper surface as wide as the reel
diameter, then assemble the parts.
2. Put the mechanism into REW mode, wait at least 10
seconds, then measure the torque value of the reel
table on the supply side. It should be at least 600 g.cm.
Take the measurement with the torque dial gauge
(VHJ-0004) held in position in your hand (lock
torque).
While taking the measurement, rotate the reel table
(take up reel assembly) on the take up side with your
hand so that the reel sensor does not respond.
3. After switching to FF mode, wait for at least 10
seconds and then measure the torque value of the reel
table on the take up side. It should be at least 600g.cm
(lock torque).
SVT-RA40/RA168
4. After switching to PLAY mode, wait for at least 10
seconds and then measure the torque value of the reel
table on the take up side. It should be between 55 and
110g.cm (lock torque).
Torque dial gauge
(VHJ-0004)
Reel table on
supply side
Fig. 4-1-1
5. After switching to REVIEW mode, wait for at least 10
seconds and then measure the torque value of the reel
table on the supply side. It should be between 100 and
210g.cm (lock torque).
Dummy cassette
tape
Stick black vinyl
tape over the tape
sensor holes.
Fig. 4-1-2
Reel table on
take up side
Make holes with
roughly the same
diameter as the reels.
2-33