DOWNLOAD Sony SLV-L45AR / SLV-L65HFAR / SLV-L75HFAR Service Manual ↓ Size: 8.49 MB | Pages: 87 in PDF or view online for FREE

Model
SLV-L45AR SLV-L65HFAR SLV-L75HFAR
Pages
87
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8.49 MB
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PDF
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Service Manual
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Device
VCR
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slv-l45ar-slv-l65hfar-slv-l75hfar.pdf
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Sony SLV-L45AR / SLV-L65HFAR / SLV-L75HFAR Service Manual ▷ View online

5-27
4-3-3. GUIDE ROLLER HEIGHT ADJUSTMENT
(See Figs. 4-3-3 and 4-3-4)
1) Play the Alignment Tape (NTSC: KRV-52NE, PAL: KRV-
52PL) and check that the envelope waveform is at its
maximum at the tracking centre. Then, after loosening
the S guide roller and the T guide roller by rotating them
anticlockwise, tighten them in turn until the envelope
waveform becomes flat. If the envelope waveform is not
at its maximum at the tracking centre, refer to section 4-
3-4 and carry out a rough adjustment of the horizontal
position of the audio R/P head (ACE head) before
adjusting the guide rollers.
2) Adjust the S guide roller.
1
 Press the tracking button (Channel – ), and check
whether, when the envelope waveform has reached
50% of its maximum, the front half of the envelope
waveform is flat. If not, fine-tune the S guide roller as
follows.
a. If the front half of the envelope waveform is as shown
in Fig. 4-3-4 (a), this means that you have pressed the
S guide roller too far. Therefore, loosen it slightly, and
when it is in the state shown in Fig. 4-3-4 (b), tighten it
again, stopping when the envelope waveform is flat.
b. If the front half of the envelope waveform is as shown
in Fig. 4-3-4 (b), this means you have not pressed the
S guide roller far enough. Therefore, tighten it slightly,
stopping when the envelope waveform becomes flat.
c. If the front half of the envelope waveform is as shown
in Fig. 4-3-4 (c), it may happen that when you tighten
the S guide roller, the wrapper waveform does not
disappear, but sinks into the flat part, as shown in Fig.
4-3-4 (d). If this happens, the status shown in Fig. 4-3-
4 (c) is normal, so loosen the S guide roller, then
tighten it again until the envelope waveform is as
shown in Fig. 4-3-4 (c).
2
 Check that at the tracking centre, the output of the
front half of the envelope waveform is not less than
80% of the maximum.
3
 Rotate the S guide roller 20
°
 anticlockwise.
3) AdjusttheTguide roller.
1
 press the tracking button (channel – ) and check
whether, when the envelope waveform is 50% of
maximum, the back half of the envelope waveform is
flat. If not, loosen the T guide roller slightly, then
tighten it gradually until the back half of the envelope
waveform becomes flat.
2
 Check that the output for the back half of the envelope
waveform is at its maximum at the tracking centre.
4) Check that the envelope waveform does not fluctuate
when you switch from F-SEARCH to PLAY or from R-
SEARCH to PLAY. If it does fluctuate, repeat steps 3)
and 4).
Normal
Pressed
too far
Not pressed
far enough
Eccentric screwdriver
(J-6082-044-A)
S guide roller
T guide roller
Do not touch
the fixed
screw
The tape should not pass along
the cylinder lead surface
Fig. 4-3-3
If the envelope waveform 
is at maximum at the 
tracking centre, adjust to 
flat.
In normal status, the waveform 
will be flat even when the 
envelope waveform is reduced 
to 50%.
100%
50%
50%
50%
50%
50%
(a) S guide roller
pressed too far
(d) S guide roller
pressed too far
(b) S guide roller not
pressed far enough
(c) Normal status for
wrapper waveform
Fig. 4-3-4
5-28
4-3-4. AUDIO R/P HEAD (ACE HEAD) HEIGHT
ADJUSTMENT, AZIMUTH ADJUSTMENT
AND HORIZONTAL POSITION ADJUST-
MENT
(l) Azimuth adjustment (See Fig. 4-3-5)
1) Play the alignment tape (NTSC: KRV-52NE, PAL: KRV-
52PL) and observe the waveform of the audio output,
using an oscilloscope.
2) Loosen the height adjustment screw in the counter-
clockwise direction and decrease the amplitude of the
audio output waveform. In this state, tighten the screw
in the clockwise direcion and maximize the amplitude.
Slightly tighten the screw further in the clockwise
direction and decrease the amplitude, and then loosen
it slowly in the counterclockwise direcion until the
amplitude starts to reach the maximum.
3) Set the amplitude of the audio output waveform to
maximum by rotating the azimuth adjustment screw.
4) Make sure that the tape edge is running between the
top of the audio head and the bottom of the control
head.
Gaps A and B should be roughly equal.
NOTE: Rotate the adjustment screw with a slotted screw-
driver. Do not apply excessive force vertically. As the
height adjustment screw also adjusts tilt, rotate it slowly.
Do not rotate it excessively. And apart from the this screw,
and height adjustment screw, the screws is precisely
adjusted before shipment from the factory, and should not
be tampered with. Tampering with these screws can lead
to scratching of the tape and other problems.
Azimuth adjustment screw
Audio R/P head assembly
(ACE Head)
Height adjustment
screw
This screws is precisely
adjusted and should not be
tampered with.
Tape
Control head
Audio head
A
B
A=B
Fig. 4-3-5
(2) Horizontal position adjustment (See Fig. 4-3-6)
1) Play the alignment tape (NTSC: KRV-52NE, PAL: KRV-
52PL).
2) Press the tracking buttons (channel + and channel – )
simultaneously and set the tracking to the centre.
3) Using an oscilloscope, observe the waveform of the
video head output.
4) Loosen the two fixed screws on the audio R/P head
(ACE head) by between 20
°
 and 30
°
 anticlockwise.
5) Using a slotted screwdriver, adjust the position of the
audio R/P head (ACE head). At the position where the
amplitude of the envelope waveform is at its maximum
at the tracking centre, tighten the fixed screw on the
audio R/P head (ACE head). When you do this, check
that the envelope waveform changes equally whether
the tracking is shifted by pressing the tracking button in
the plus or the minus direction.
6) Play the alignment tape (NTSC: KRV-52NE, PAL: KRV-
52PL) and check that the amplitude of the envelope
waveform is at its maximum at the tracking centre. If
not, repeat steps 1) to 6).
7) Refer to the electrical adjustments section of the service
manual, and adjust the switching position of the servo
circuit.
NOTE:
1. When you press the tracking buttons (channel+ and
channel – ) simultaneously, the tracking is reset to the
tracking centre. When the tracking is at the tracking
centre, the message “T - : - “ will appear in place of the
clock display on the front panel. If you keep pressing the
channel– button the messages “T- : “ and “T - - : “ will
appear, while if you keep pressing the channel + button,
the messages “T : - ” and “T : - - “ will appear. Three
seconds after you stop pressing the tracking buttons, the
clock displav will re-appear.
2. The check described in paragraph 6) is not necessary
for models in which the only tape speed is SP mode.
Audio R/P head assembly
Scew
Screw
Slotted
screwdriver
After resetting the tracking to the
tracking centre, set the envelope
waveform to maximum.
Fig. 4-3-6
5-29
E
Fig. 4-3-7
4-3-5. CHECKING AFTER ADJUSTMENT
1) Play the alignment tape (NTSC: KRV-52NE, PAL: KRV-
52PL) and check that the envelope waveform is
activated immediately and that there are no fluctuations
in the envelope waveform or the audio output wave-
form.
2) Load a cassette tape (NTSC:T-120, PAL: E-180) and
use it to record and replay. Check that the envelope
waveform is activated immediately and that there are
no fluctuations in the envelope waveform or the audio
output waveform. (When recording on the tape, input
1kHz to the audio input terminal. Use a scratch-free
cassette tape (NTSC: T-120, PAL: E-180).) Check that
at the tracking centre, the front half down and back half
down are not more than 20% of the value at the point
where the envelope waveform amplitude is at its
maximum.
3) Check that the envelope waveform is activated immedi-
ately when you switch from PLAY to R-SEARCH or
from R-SEARCH to PLAY. Check that there is no slack
in the tape next to the pinch roller.
4) Check that the envelope waveform is activated immedi-
ately when you switch to PLAY from FF, REW, F-
SEARCH, R-SEARCH or STOP mode. Check that there
is no slack in the tape next to the pinch roller.
5) Check that the tape is not curling or riding up on the
upper or lower flanges of the tape guides in PLAY, FF,
REW, F-SEARCH or R-SEARCH modes.
6) Check that in PLAY mode. the tape runs as shown in
Fig. 4-3-7.
7) Load a tape (NTSC:T-160, PAL: E-240) and play it
back. carry out the checks described in steps 3) to 5)
above.
No. 0 tape
guide
S tape guide
S guide
roller
Cylinder
(drum)
T guide roller
Audio R/P head assembly
(ACE head)
T tape guide
Loading guide
post
BT post
Full erase
head
Pinch roller
Capstan shaft
6-1
SECTION 6
ELECTRICAL ADJUSTMENTS
CIRCUIT BOARDS LOCATION
CP-1 PWB Assembly
TM-1 PWB
TM-2 PWB
VP-1 PWB Assembly
3 in 1 Tuner
(Tuner/IF/RF Conv.)
SLV-L45AR/L65HFAR/L75HFAR
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