Sony SVT-RA168, Service Manual

Page: 47 / 100

2-31
SVT-RA40/RA168
3-18. Tape Sensors, Reel Sensor and
EP SW Lever
3-18-1. Tape Top Sensor and Tape End
Sensor
1. Refer to Section 3-2 and remove the mechanism unit.
2. Refer to Section 3-3-1 and remove the cassette mecha-
nism assembly.
3. Remove the soldering from the MC-1 PWB assembly,
then remove the photo diodes
1
,
2
and the LED
3
.
When removing the photo diode
2
on the tape top
sensor side, refer to Section 3-15 and remove the main
cam.
Assembly Notes:
1. Fit the photo diodes
1
and
2
so that their photore-
ceptors to face the LED
3
, as shown in Fig. 3-18-1.
Align the cuts in the LED
3
and the holder
4
.
Push the photo diodes
1
,
2
and the LED
3
as far
down as they will go, so that they do not protrude
above the top of their holders.
2. Do the soldering quickly.
Fig. 3-18-1
3-18-2. Reel Sensor
1. Refer to Sections 3-12-2 and 3-12-4, then remove the
clutch mounting assembly, the T soft brake assembly
and the take up reel assembly.
2. Refer to Section 3-13-2, then remove the wheel gear 2,
the wheel gear 1, and the brake control lever.
3. Remove the soldering from the MC-1 PWB assembly,
then remove the photo diode (reel sensor)
1
.
Assembly Notes:
1. When assembling the parts, align the cut on the photo
diode (reel sensor)
1
with the protrusion on the
mechanism chassis
2
.
2. Do the soldering quickly.
Fig. 3-18-2
3
LED
Holders
4
Holder
Holders
Front
Turn the photoreceptors to
face the LED
3
2
Photo
diode
(Tape top
sensor)
2
Photo
diode
(Tape end
sensor)
Align the cuts
2
Protrusion
Cut
1
Photo diode
(reel sensor)
Mounting shaft for
take up reel assem-
bly