Salora SV8720 User manual

SALORA
HUOLTO -SERVICE
SERVICE-MANUAL
VIDEO TAPE RECORDER SV8720
Tape Format
Power Source
Power
Consumption
Television System
Video Recording
System
Luminance
Colour Signal
Audio Track
Tape Speed
Record/Playback
Time
Heads: Video
Audio/
Control
Erase
ZB1276 09.87 .
| VHS | Only cassettes marked VHS can be used with this video cassette recorder.
SPECIFICATIONS
: VHS 1/2" high-density video
cassette tape
: 220V AC; 50Hz
. Approx. 23W
: PAL colour and CCIR
monochrom signal (System B &
G) 625 lines, 50 fields
: 4rotary heads, azimuth helical
scanning system
: Frequency modulaticn
recording
: Low frequency conversion
sub-carrier phase shift
recording
> 1 track
: 23.39 mm/sec (Standard Play)
: 11.7 mm/sec (Long Play)
: 240 min. with E-240 cassette
(Standard Play Mode)
: 480 min with E-240 cassette
(Long Play Mode)
: 4rotary single crystal heads
: 1 stationary head
: 1 full track head
Video Input
Audio Input: Line
Video Output
Audio Output
TV Tuner
Operating
Temperature
RF Channel Output
Weight
Dimensions
Timer
Channel Selection
: 0.7510 1.5 Vp-p, ohm
unbalanced Scart sc ket
- —8dBs, 50K ohmin balanced
Scart socket
:
1.0Vp-p,
75
ohm
wp
alanced
Scart socket
: —8dBs, 1K ohm up @lanced
Scart socket
> VHF 2~12CH
UHF 21 ~69CH
CATVS1‘ ~ $3’, Si1— S20
> BC to 40°C
: Set to Channel 36
Channel 32 — Chan €! 40
Selectable
: Approx. 5.8 kg
- 424 mm (W) x 92 ne {H)
x 310 mm (D)
- 7 programs for anyckannels in
two weeks/every ay” _
1 program for any nzenneis In
every week day
24 hour digital synh a Onized with
crystal oscillator friq #eNcy.
- 30 position UP/DOY ™N
(Voltage synthesize =selector)

CONTENTS
Disassembly
...............0::::ccccecsceereettteetnneeees
1
How
to
execute
Circuit
Board
service
..........
2
Cleaning
oo...
ec
eecee
eter
ere
tee
eee
eteertettaes
4
Mechanical
&
Electrical
Adjustment
TOOISS
oo
efxkcehiie
ee
eee
5
Major
component
removal
and
installation
...................00-:c
eee
f)
4-1
Picture
Control
Adjustment
...................55
7
1-2
Still
Adjustment
20...
ee
7
2.
Removal/Replacement
of
Primary
Parts
..0.0...0..0000
cee
eee
7
2-1
Replacement
of
Cassette
Housing
............
7
2-2
Replacement
of
Drum
Motor/Video
Head
ASSEMDIY
........eccceceeeceeeteteteettees
8
2-3
Replacement
of
Upper
Drum
.............
Ss)
2-4
Replacement
of
Capstan
Motor
..............5
9
2-5
Replacement
of
Belt
Ro...
ee
10
2-6
Replacement
of
Loading
Motor
..............-5
10
2-7
Replacement
of
Pinch
Roller
..............
10
.
Electrical
Adjustments
.................
ee
11
3-1
Servo
Circuit
Adjustments
............
ee
12
3-2
Y/C
Signal
Circuit
Adjustments
..............-
12
3-3.
Audio
Circuit
Adjustments
...............
ee
14
ne
4.
Mechanical
Adjustments
................0.....:.:05
15
4-1
Tension
Pole
Position
Adjustments
............
15
4-2
Installation
of
Master
Plane
Jig
.............0.
15
4-3. Supply Impedance Roller and Take-up
Guide Pole Height Check and
ACJUSTMENE ...c sed seetinnnea taney aes 15
4-4 Reel Disc Height Check and
AGJUStMONT cas cise anaes sas 16
4-5 Arm Take-up Guide Pole Height
AdjUStMENE oo... eee ee eee rete eres 16
4-6 Back Tension Check and
ACjUStMENt oo... eee cette teeter 16
4-7 Positioning of Gears and their
Installation SEQUENCE ....... ee cee 17
4-8 Mode Switch Attachment and
AdjUStMENE
oo...
eee
cece
eect
eeteeteeneees
17
4-9
Half
Loading
Unit
Adjustment
..............05
18
4-10
Tape
Path
Check
and
Adjustmen:
.
............
me)
4-11
Interchangeability
Adjustments
...
0.0.0...
.,
KEY
TO
ABBREVIATIONS
.................
-.005
25
Parts:
List
.
3c
canes
seoniec
eels
26
1.
CABINET
ASSEMBLY
..........c
ce
crete
26
2.
DECK
ASSEMBLY
0.0...
cceeecceeee
eee
etteeenees
27
3.
ELECTRICAL
PARTS
.0.....
ccc
eccceccuce
ceteris
31
4.
PACKING
PARTS.
.......ccccccceeeeeeeeenee
tetreeetenes
34
Circuit Diagrams
cee

DISASSEMBLY
1.
REMOVAL
OF
TOP
COVER
A.
As shown in Figure 1, remove the four screws
®. ©. © and ©), two on each side, retaining
the top cover.
Gently expand the bottom edges of the top
cover, pivot cover forward, then slide toward
rear, in the direction of the arrows.
2. REMOVAL OF FRONT PANEL
A.
B.
Remove screw at @.
Unfasten the seven snaps (©), ©. ©. ©. ©. ©
and @) and remove the front panel in the
direction shown by the arrows.
3. REMOVAL OF BOTTOM COVER
A. Remove the seven screws (©, ©, ©. O. ©. ©.
and @) retaining the bottom cover as shown in
Fig. 3.
. Remove the bottom cover by sliding toward the
rear side and pulling outward in the direction of
the arrow.

HOW
TO
EXECUTE
CIRCUIT
BOARD
SERVICE
CAUTION: BEFORE ATTEMPTING TO RE-
MOVE OR REPAIR ANY PCB
UNPLUG THE POWER CORD
FROM THE A.C SOURCE BES SIONS!
Location of Printed Circuit Boards (Refer to Fig. 4)
PCB-TIMER
PCB-OPE
1. PCB SIGNAL
A. Remove 4 retaining screws on the top side (@,
®,. © and ©) and 2 retaining screws (© and ©)
on the rear side of the signal circuit board,
which is shown in Fig. 5.
B. Open the circuit board in the arrow marked
direction, letting the right side hook hang on the
base chassis.
2. PCB CONTROL/POWER
A. Remove the signal circuit board which is given
in Item (1).
B. Remove the bottom cover, (Refer to Item (3) on
page 1).
In general, under the circumstances, the ser-
vice of the control circuit board will be available.
C. Removing two retaining screws (© and ©)
which are shown in Fig. 6, raise up and remove
the circuit board.
PCB-SIGNAL

3.
PCB
OPE
A.
Unlock
the
PCB
Ope
Supporter
@,
as
shown
in
Fig.
7.
B.
Remove
the
PCB
Ope.
Supporter @
4. PCB TIMER
A.
Unlock
the
two
PCB
Timer
Supporters
(@
and
®) as shown in Fig. 8.
B.
Remove
the
PCB
Timer.
5. PCB Power SUB
A.
Remove
the
three
screws
(@,
and
©)
retaining
the
PCB
power
sub
as
shown
in
Fig.
9.
B.
Remove
the
screw
©
retaining
the
Cover
Power as shown in Fig. 9.

CLEANING
The following items require cleaning after servicing to
maintain satisfactory performance.
1. VIDEO HEAD CLEANING
A.
B.
C.
Remove the top cover. (Refer to item 1 on page
1)
Remove the Stay-Stopper-C. (Refer to item
2-1-1 C on page 7)
Moisten a clean piece of chamois with a
professional head cleaning solution. Hold the
chamois to the drum assembly and rotate the
drum clockwise by hand to clean the video
heads and tape path.
NOTE:
Never move the chamois vertically while clean-
ing, otherwise the heads will be damaged.
After the heads are cleaned, allow the cleaned
portion to dry thoroughly before running a tape,
otherwise the tape and head may be damaged.
2. TRANSPORT SYSTEM
(The transport mechanism should be cleaned after
every 500 hours of use to maintain proper operation.)
A. The following components of the transport
system require occasional cleaning:
© S.SLANT POLE
© S.GUIDE ROLLER
@® FE HEAD
@ S.IMPEDANCE-ROLLER
A D ‘
Gj
@ TENSION POLE fe . ZZ
@ sP-GuDE fq
OLE q
“4
@ UPPER & LOWER DRUM
@
TENSION
POLE
@FE
HEAD
@
SP-GUIDE
POLE
@
S.IMPEDANCE-
ROLLER
®©S.GUIDE ROLLER ©S.SLANT POLE
@ UPPER & LOWER = @T.U SLANT POLE
DRUM
©®T.U. GUIDE ROLLER @ A/C HEAD
@T.U.GUIDE POLE @CAPSTAN SHAFT
@ PINCH ROLLER SHAFT-TU-GUIDE
To clean, use a small piece of gauze moistened
with alcohol.
Use extreme care when cleaning the video
heads and Drum assembly to prevent damage.
Avoid touching the Drum assembly with your
fingers which would deposit skin oil on it.
NEVER clean the Drum assembly by moving
the cleaning pad vertically.
. After cleaning transport mechanism, allow it to
dry thoroughly before loading a tape. /f this is
not done damage to the heads or tape may
result.
3. REEL DRIVE SYSTEM
A. Reel Disc Brake Surfaces require occasional
cleaning using a small piece of gauze mois-
tened with alcohol.
T.U SLANT POLE
© T.U. GUIDE ROLLER
A/C HEAD
@ T.U. GUIDE POLE
@ CAPSTANSHAFT

MECHANICAL
&
ELECTRICAL
ADJUSTMENT
TOOLS
PURPOSE
METHOD
|
Adjustment
Driver
(859C25900)
Fa a i sia
The
adjustment
driver
is
intended
to
adjust
variable
resistors,
trimmers,
transformers
etc.
in the circuitry.
Select
a
tip
suitable
for
the
particular
head
of
the
component
concerned
and
adjust.
Dummy Cassette
and soak-testing.
The
dummy
cover
masks
the
start
and
end
sensors
and
turns
the
cassette
switch
on.
(859C34702)
=
dummy
cover
is
loaded
instead
of
the
cassette
tape
in
repair,
inspection,
adjustment
Load
the
dummy
cover
in
the
cassette
housing
instead
of
the
cassette
tape.
|
Hex Keys (1.5mm)
.*
(859C25902) (859C25905)
Alignment Tape (MH-2 PAL) (59C33901)
The
hex
keys
are
used
for
tightening
or
remov-
ing
hexagonal
socket
head
screws
which
fasten
the
guide
rollers
of
the
supply
and
take-up.
Standard signals (VHS Standard) are recorded
on the alignment tape and reproduced when
required in the adjustment of Y/C circuit, audio
circuit and interchangeability alignment.
and turn.
ordinary tape.
u
Insert
the
given
size
(1.5mm)
hexagonal
socket
Install
and
run
in
the
play
mode,
the
same
as
for
_
Back Tension Gauge (859C34508)
The back tension gauge is used for measuring
the tension of the tape on the supply side.
Load
this
gauge
in
the
cassette
fhousing
and
run
in
the
play
mode.
Read
the
gauge
indicator.
(859C34500)
(859C34501) |
The torque meter is used for measuring the
torque of the reel disc brake, “FF” and “REW”,
Take-up etc.
+.
on the reel disc.
Measure
the
“FF”
and
“REW”
take-up
torque
by
rotating
the
meter
at
the
Same
speed
by
hand
and
reading
the
scale
indicator.
Measure
the
brake
torque
by
setting
the
meter
~

PURPOSE
METHOD
Master Plan Jig
(859C34107)
The height gauge and the master plane are used
for measuring height and perpendicularity of the
heads, rollers, reel discs, etc. of the tape path.
The master plane ts set on the main deck and
the height gauge is applied to the part being
measured.
|
y
|
|
|
|
|
Grip ring fixer
(859C34705)
A tool for preventing the grip ring from opening
excessively.
|
While opening the grip ring with the tips of this
tool, install the grip ring on to the shaft.
a
REC Current Adjustment Jig
(859C34706)
ay
The REC Current Adjustment Jig is use for FM
record level adjustment and Recording colour
level adjustment.
{
Use in conjunction with oscilloscope. For deteil |
refer to the service manual.

MAJOR
COMPONENT
REMOVAL
AND
INSTALLATION
1-1
PICTURE
CONTROL
ADJUSTMENT
VCR
picture
quality
may
be
adjusted
according
to
personal
preference:
Rotate
the
picture
control
knob,
located
as
shown
in
Fig.
1,
to
achieve
the
desired
picture
quality.
1-2
STILL
ADJUSTMENT
There
are
some
cases
where
the
picture
bounces
vertically
in
the
STILL
mode
when
VIDEO
CASSETTE
was
recorded
on
another
VCR.
In
such
a
case,
adjust
the
still
knob,
located
as
shown
in
Fig.
1,
until
bouncing
stops.
2.
REMOVAL
OF
PRIMARY
PARTS
2-1
Replacement
of
Cassette
Housing
2-1-1
Removal
A.
Remove
the
Top
Cover
and
Front
Panel.
B.
Place
the
PCB
signal
vertically
in
the
service
position.
C.
Remove
the
screw
@
retaining
the
Stay
Stop-
per
C,
as
shown
in
Fig.
2-1(A).
D.
Remove
the
Stay
Stopper
C.
—£.
Remove
the
two
screws
(@)
and
©)
retaining
the
Stay
front
as
shown
in
Fig.
2-1(A).
F. Remove the Stay front.
G.
Remove
the
Cassette
Housing
loading
belt
as
shown
in
Fig.
2-1(B).
H.
Disconnect
connector
[CT],
as
shown
in
Fig.
2-1(C).
Remove
the
two
screws
(®
and
@®)
retaining
the
Cassette
Housing
as
shown
in
Fig.
2-1(C).
J.
Remove
the
Cassette
Housing
by
sliding
back
in
the
direction
of
the
arrow.
STILL ADJ
PICTURE CONTROL
Fig. 1
Cassette Housing loading belt
Fig. 2-1(B)
Connector
Fig. 2-1(C)

2-1-2 Replacement
To
reassemble
the
cassette
housing
into
the
VCR
adhere
to
the
following
steps.
If
these
steps
are
not
carried
out
properly,
abnormal
noise
may
be
produced
in
the
FF
and
REW
modes
or
the
tape
may
be
damaged
in
playback.
A.
Place
the
PCB
Signal
vertically
in
the
service
position.
B.
Set
the
positioning
U-holes
at
the
right
and
left
front
of
the
cassette
housing
sides
onto
the
pins
at
the
front
side
of
the
main
transport
plate,
refer
to
Fig.
2-1(C),
then
slide
the
cassette
housing
inside
to
the
point
where
the
holes
for
the
housing
screws
are
matched
to
the
screw
holes
on
the
main
plate.
Install the two cassette housing screws.
Reconnect connector
Attach the cassette housing loading belt shown
in Fig. 2-1(B).
F.
Attach
the
stay
front
as
shown
in
Fig.
2-1(A).
G.
Attach
the
Stay
Stopper
C
as
shown
in
Fig.
2-1(A).
H.
Check
that
the
cassette
is
loaded
and
unloaded
smoothly
without
abnormal
noise.
|. Check that, in the unloaded position, the loading
prevention latch attached to the bottom of the
cassette housing is fastened to the housing
side strip. (See Fig. 2-1 (D))
J.
If
an
irregularity
is
detected
in
steps
(H)
and
(I)
the
cassette
housing
may
be
incorrectly
assem-
bled.
Loosen the fastening screws, unfasten the
cassette housing and readjust, as required.
moo
Loading prevention latch
Fig. 2-1(D)
2-2 Replacement of Drum Motor/Video Head
Assembly
2-2-1 Removal of Drum Motor/Video Head
Assembly
Remove the Bottom Cover.
Remove the Stay Stopper C.
Remove the Regulator Transistor fastening
screw as shown in Fig. 2-2(A) and remove the
Regulator Transistor.
D. Remove the three drum retaining screws as
shown in Fig. 2-2(B).
E. Holding the upper drum assembly, remove the
complete Drum Motor/Video head assembly by
gently pulling in an upward direction.
F. Disconnect connectors [DA]and from Drum
assembly.
Cro
Fig. 2-2(A)
Fig. 2-2(B)
2-2-2 Installation of Drum Motor/Video H ead
Assembly
During installation, avoid holding the upper drum with
bare hands. If this cannot be avoided, a cleaning
procedure must be performed as described in ”Clean-
ing” section, on page 4, upon completion of installa-
tion.
A. Reconnect connectors [DA] and
B. Carefully holding the complete drum assembly
(with a piece of cotton cloth), slowly #nsert the
drum assembly into its original drum snounting
position.
Note:
Do not apply excessive force to the vid €0 heads
as damage will result.

C.
D.
E.
Secure with the three drum retaining screws
previously
removed,
as
shown
in
Fig.
2-2(B).
Fasten
the
Regulator
Transistor
mounting
screw.
When
the
complete
drum
assembly
has
been
changed,
precise
alignment
requires
checking.
Check
and
adjust
playback
switching
point,
tracking
preset,
color
recording
level,
FM
re-
cording
level
and
interchangeability.
2-3 Replacement of Upper Drum
2-3-1 Removal of Upper Drum
A. Remove the brush fastening screw, as shown
in Fig. 2-3(A) and remove the brush.
B.
Unsolder
the
terminals
®.
©,
©
and
@
as
shown in Fig. 2-3(A).
Brush
Screw
Terminal @
Fig. 2-3(A)
C. Remove the two upper drum fastening screws
as shown in Fig. 2-3(B), and gently pull the
upper drum in an upward direction.
Fig. 2-3(B)
2-3-2
Installation
of
Upper
Drum
Note
Extreme
care
must
be
exercised
when
handling
the
Video
Heads.
A.
B.
C.
D.
install the new upper drum to the lower drum
as shown in Fig. 2-3(B).
install the two upper drum mounting screws.
(Fastening them one after the other)
Solder the terminals @. ®. ©. ©, ©. ®, © and
@ as shown in Fig. 2-3(A).
Fasten the brush with the brush retaining screw
as shown in Fig. 2-3(A).
2-4 Replacement of Capstan Motor
2-4-1 Removal of Capstan Motor
On the underside of the transport deck, remove
the two stopper-RD retaining screws (® and ®)
as shown in Fig. 2-4(A).
Remove the belt-R.
Remove the three Grip Rings (©, © and ©)
retaining the Link B and remove the Link B as
shown in Fig. 2-4(A).
Disconnect connector as shown in Fig.
2-4(A).
Remove the three screws retaining the Capstan
motor as shown in Fig. 2-4(B).
2-4-2 Installation of Capstan Motor
Fasten the Capstan motor with the three
Capstan motor retaining screws as shown in
Fig. 2-4(B).
Reconnect connector as shown in Fig.
2-4(A).
Install Link B so the pin fits in the outside slot of
CAM-GEAR-M, install the grip rings at three
locations.
install Belt-R and Stopper-RD.
Clean the capstan shaft after its installation
complete by wiping with alcohol, etc.
OF
ee Stopper-RD
Qos,
Grip ring
Connector [BC]
Fig. 2-4(A)
Capstan motor
retaining screw
Fig. 2-4(B)

2-5 Replacement of Belt R
2-5-1
A.
B.
c.
Removal of Belt R
Remove the two screws (@ and ©) retaining
the
stopper-RD
as
shown
in
Fig.
2-5.
Remove the two rotor thrust bearing retaining
screws (© and ©) as shown in Fig. 2-5.
Lift the rotor thrust bearing a little and remove
the belt R as shown in Fig. 2-5.
2-5-2 Installation of Belt-R
A.
A new Belt-R shall be installed according to the
reversed sequential order (from Item © ~ Item
@) in paragraph 2-5-1.
2-6 Replacement of Loading Motor
2-6-1 Removal of Loading Motor
A.
B.
C
D.
Disconnect connector on the PCB CON-
TROL.
Remove the cassette housing loading belt as
shown in Fig. 2-6(A).
. Remove the two screws retaining the Holder as
shown in Fig. 2-6(A).
Remove the loading belt as shown in Fig.
2-6(A).
. Unlock the three supports (@, ® and ©) shown
in Fig. 2-6(A) and remove the Holder-Worm.
Unlock the two Motor Supports (© and ©) as
shown in Fig. 2-6(A) and remove the Loading
motor.
Holder retaining screw
Cassette housing
Loading belt
Fig. 2-6(A)
2-6-2 Installation of Loading Motor
Note:
When the LEVER-TRIG which is shown in Fig.
2-6(B) is removed it shall be installed as shown in
Fig. 2-6(C).
A.
Following the reverse sequential order (from
Item © ~ Item @) in paragraph 2-6-1 to install a
new loading motor.
Lever Trig
Fig. 2-6(B)
Fig. 2-6(C)
2-7 Replacement of Pinch Roller
A.
B.
C.
Pull the Pinch Roller Cap upward to remove.
(Refer to Fig. 2-7).
Insert the new Pinch Roller. (Refer to Fig. 2-7).
Replace the Pinch Roller Cap. Make sure that
the direction of the Cap is within the range
shown in Fig. 2-7.
Note:
It is advisable, when replacing the Pinch Roiler
Cap, to support the Arm-pinch fron underneath
to prevent it from being bent during this
operation.
20°+5°
Pinch Roller

3.
ELECTRICAL
ADJUSTMENT
Circuit
adjustments
become
necessary,
in
most
cases,
due
to
the
wear
of
mechanical
parts
or
following
the
replacement
of
critical
components
such
as
the
video
head.
Certain
circuit
defects
can
often
cause
circuit
adjustments
to
vary
considerably.
Should
this
occur,
be
sure
to
determine
the
nature
of
the
defect
and
repair
prior
to
proceeding
with
adjustments.
PCB
CONTROL
(Parts
side)
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Always
use
the
test
equipment
recommended
for
a
given
adjustment
procedure.
If
the
appropriate
test
equipment
is
not
available,
it
is
recommended
that
adjustments
NOT
be
attempted.
Refrain
from
the
indiscreet
adjustment
of
circuit
controls
unless
proper-
ly
equipped
to
do
so.
Rend
NOISE CANCEL ADJ

3-1 Servo Circuit Adjustment
3-1-1
Playback
Switching
Point
Adjustment
A.
B.
C.
{+}
slope
3-1-2
A.
B.
C.
Turn the tracking control VR480 to centre click
stop position.
Playback the grey scale step signal of the
alignment tape.
Connect the oscilloscope’s EXT trigger to TP-2H
on the PCB-SIGNAL.
Set the EXT TRIGGER to “—".
Connect the oscilloscope to the video output
socket or TP-2J and adjust VR4A0 so that the
trigger point is located at 6.5 + 1H before the
vertical synchronizing signal, Fig. 3-2.
Set the EXT TRIGGER to “+”.
Check that the trigger point is located 6.5 + 1H
before the vertical sync signal, Fig. 3-2.
DIV 20mV (X10)
TIM SOusec
J
ry
j if 7
i , ff Equalizing pulse
fo¢
oy
pay)
7? oe, yn ae
'
t
Pe
ooh
4H
2.5H
<<<}
pons
ap png
oe ae ae, V.SYNC
WU
gow CR SE aden en
ae,
vo
rr
ee
Fig. 3-2
Tracking Preset Adjustment
Turn the tracking control VR480 to the centre
click stop position.
Playback
the
selfrecorded
tape.
(LP
mode)
Connect
CH1
of
the
oscilloscope
to
TP4A
and
CH2
to
TP4B
on
PCB
CONTROL.
Adjust
VR4A1
so
that
the
falling
edge
of
TP4A
coincides
with
the
falling
edge
of
TP4B
as
shown
in
Fig.
3-3.
B.
C.
3-2
Y/C
Signal
Circuit
Adjustment
3-2-1
CCD
Bias
Adjustment
A.
Playback the colour bar signal of an alignment
tape.
Connect an oscilloscope to test point TP-2R on
PCB-SIGNAL. .
Adjust VR2A3 so that the SYNC signal and
upper side of waveform is not strained, as
shown in Fig. 3-4.
DIV 5mvV (X10)
TIM 10pusec
3-2-2 Noise Cancel Adjustment
Playback the colour bar signal of an alignment
tape.
Connect an oscilloscope to test point TP-2L on
PCB-SIGNAL.
Adjust VR2A2 so that the video signal dis-
appears.
if noise remains after the video signal dis-
appears, adjust VR2A3 slightly counter clock-
wise as seen from parts side so that the noise is
minimum.

3-2-3
AFC
Adjustment
A.
Set
the
INPUT
SW
to
CAMERA
Position.
B.
Short
circuit
Pin
@
and
Pin
@
of
VIDEO/AUDIO
terminals
shown
in
Fig.
3-6.
C.
Ground
test
point
TP-6B
(Pin
@
of
IC6A0)
and
test
point
TP-6D
(Pin
@
of
IC6A0)
on
PCB
SIGNAL
and
set
the
recorder
to
STOP
mode.
D.
Connect
a
frequency
counter
to
TP-6C
on
the
PCB
SIGNAL.
—.
Adjust
VR6A2
so
that
the
frequency
at
TP-6C
is
623KHz
+
5KHz.
9090000000)
MAYS)
VIDEO/AUDIO TERMINAL
(Scart socket)
Fig. 3-6
3-2-4 Xtal OSC Adjustment
A.
Playback
the
colour
bar
section
of
an
alignment
tape.
B.
Connect
a
frequency
counter
(4.43MHz
OUT)
on
the
PCB
SIGNAL.
C.
Adjust
VC6AQ
so
that
the
frequency
at
TP-6J
is
4.433619MHz + 10Hz.
3-2-5
Carrier
Leak
(chroma)
Adjustment
A.
Playback
the
colour
bar
section
of
the
alignment
tape.
B.
Connect
an
oscilloscope
to
TP-2J
on
PCB-
SIGNAL.
C.’
Adjust
VR6A1
Carrier
Leak
for
minimum
ampli-
tude
at
the
point
shown
in
Fig.
3-7.
to TP-6J
DIV 20mvV {X10}
TIM 10sec
3-2-6
FM
Record
Level
Adjustment
A.
Supply
an
RF
signal
(colour
bar)
to
the
recorder
and
set
it
to
the
LP
RECORD
mode.
B.
Connect
the
oscilloscope
to
TP-2Y
and
TP-2X
with
a
pad
(REC
CURRENT
ADJ
JIG:
859C34706)
on
the
PCB
SIGNAL
as
shown
in
Fig.
3-8.
C.
Turn
the
VR6AO
fully
clockwise
as
seen
from
parts
side
of
the
PCB
SIGNAL.
D.
Adjust
VR2A0
(REC-LEVEL)
on
PCB-SIGNAL
for
a
level
of
200mVp-p,
as
shown
in
Fig.
3-9.
PAD (REC CURRENT ADJ JIG: 859C34706)
3 RC Yaw eae
3300-J
4)
! Oscilloscope probe
+ (10:1)
To Head AMP Shield plate
Fig. 3-8
200mVp-p
DIV 5rnV (x10)
TIN 10Opsec
Fig. 3-9
3-2-7 Recording Colour Level Adjustment
A.
Supply
an
RF
signal
(colour
bar)
ta
the
recorder
and
set
it
to
the
LP
RECORD
mode.
B. Short circuit both extremes of R206.
C.
Connect
the
oscilloscope
to
TP-2Y
and
TP-2xX
with
a
pad
(REC
CURRENT
ADJ
JIG:
859C34706)
on
the
PCB
SIGNALas
shown
in
Fig.
3-8.
D.
Adjust
VR6AO0
for
a
level
of
54mVpe-p,
as
shown
in
Fig.
3-10.
54mVp-p
Dy 1 Omv
Ti 1 Opsec

3-3 Audio Circuit Adjustment
3-3-1
A.
B.
3-3-2
Playback Level Adjustment
Playback the colour bar section of an alignment
tape.
Connect an AC voltmeter to Pin @ (AUDIO
OUT) with AC voltmeter GND to Pin @ of Scart
socket.
Adjust VR3A1 (PB-LEVEL) for an output level of
—8dB.
Bias Level Adjustment
Connect a Capacitor between Pin @ and Pin @
of the Scart socket (Refer to Fig. 3-11) and set
the recorder to RECORD mode.
Connect an AC voltmeter with a probe (high
pass filter) to TP-3E and TP-3F as shown in Fig.
3-12.
Note:
Be careful that the AC voltmeter housing does
not touch the VCR chassis.
Confirm that the monitor TV etc. does not affect
the indication of the AC voltmeter and then
adjust VR3A0 (BIAS LEVEL) for 2.20mV.r.m.s.
Note:
Do not set the VCR to PLAY mode with the AC
voltmeter connected. (The audio amplifier will
be over-loaded.)
Scart socke

4.
MECHANICAL
ADJUSTMENT
4-1
Tension
Pole
Position
Adjustment
A.
Cover
the
END
SENSOR
with
a
small
piece
of
B.
Note:
tape
and
set
the
recorder
to
the
playback
mode.
During
the
playback
mode,
make
sure
that
the
tension
pole
is
within
the
range
as
shown
in
Fig.
4-1{A).
If
the
tension
pole
is
outside
the
range,
move
the
holder
shown
in
Fig.
4-1(B)
and
adjust
the
position
of
the
tension
pole.
Tension
pole
Fig. 4-1(A)
Tension arm
SP Reel disc
Tension Brake
When
using
a
dummy
cassette
which
has
been
supplied
for
current
service,
there
are
often
the
cases
where
the
dummy
cassette
sticks
inside
the
deck,
and
cannot
be
removed
easily.
To
prevent
this
occurence
cut
out
the
sections
of
the
dummy
cassette
shown
in
Fig.
4-1(C).
Dummy cassette
Fig. 4-1(C)
4-2
Installation
of
Master
Plane
Jig
A.
B:
mo
Remove
the
Top
Cover
and
Front
Panel
of
the
recorder.
Insert
a
dummy
cassette
in
the
cassette
hous-
ing
and
engage
the
play
mode
to
bring
about
the
loaded
condition.
(i.e.
when
the
VCR
is
loaded
with
either
a
cassette
tape
or
dummy
cassette)
After
loading
has
been
completed
remove
the
power
cord
from
the
AC
source.
Remove
the
cassette
housing.
Ensure
that
the
surface
of
the
transport
deck
is
free
from
any
dust,
dirt,
or
foreign
matter
and
install
the
master
plane
jig,
as
illustrated
in
Fig.
4-2.
Master Plane
4-3
Supply
Impedance
Roller
and
Take-up
Guide
A.
B.
Pole
Height
Check
and
Adjustment
Install
the
master
plane
jig
as
described
in
item
4-2.
By
using
the
height
adjust
square,
make
sure
that
the
collar
at
the
bottom
of
the
take-up
guide
pole
slides
under
part
@®
of
the
square
but
not
under
part
®)
as
shown
in
Fig.
4-3.
Make
sure
that
the
flange
at
the
bottom
of
the
supply
Impedance
roller
slides
under
part
@
of
the
square
but
not
under
part
@
as
shown
in
Fig.
4-3.
In
this
case,
use
the
height
adjust
square
with
the
“SP”
mark
to
check
the
Supply
Impedance
roller,
and.
the
height
adjust
square
with
the
“TU” mark
to
check
the
take-up
guide
pole.
Note:
When
no
problem
is
involved
with
the
transport
system,
it
is
not
necessary
to
adjust
the
deviations
even
if
they
are
involvecd
in
the
Items
(B}
and
(C).

Height
adjusting
nut
Height
adjiusting
nut
Supply Impedance Master Plane
roller
Fig. 4-3
D.
When
Items
B
and
C
are
not
fulfilled,
height
check
shall
be
executed.
4-4
Reel
Disc
Height
Check
and
Adjustment
A.
Install
the
master
plane
jig
as
described
in
4-2.
B.
Make
sure
that
the
supply
reel
disc
and
the
take-up
reel
disc
rotate
smoothly
when
the
tension
brake
and
the
take-up
sub-brake
are
released
by
hand.
*
If
not
rotating
smoothly,
check
to
be
sure
they
are
not
being
hindered
by
the
brake
shoe
or
contact
from
adjacent
components.
*
Make
sure
that
the
reel
disc
shaft
is
free
from
binding.
C.
Examine
the
height
of
the
reel
disc
with
the
“Height
Adjust”
square
as
illustrated
in
Fig.
4-4.
The
reel
disc
height
should
be
between
levels
A
&
B
of
the
square
as
illustrated.
D.
Inspect
the
height
in
two
directions
at
right
angles
to
each
other.
If
necessary
adjust
the
height
of
the
Reel
discs
by
adding
or
removing
poly
slider
washers
(552C00604:
0.13mm).
Reel disc Height
adjust square
16
4-5
Arm
Take-up
Guide
Pole
Adjustment
A.
B.
Install
the
master
plane
jig
as
described
in
4-2.
Place
the
“Height
Adjust”
Square
on
the
master
plane
and
be
sure
that
the
lower
flange
of
the
arm
take-up
guide
pole
is
level
with
the
lower
edge
of
the
“TU-G”
side
of
the
square.
If
the
flange
height
deviates,
adjust
it
with
the
height
adjust
nut.
Arm T.U. Guide Pole
Height adjust nut
Master Plane
4-6
Back
Tension
Check
and
Adjustment
A.
B.
C.
Insert
the
Back
tension
meter
and
set
the
recorder
to
the
playback
mode.
Check
that
the
mean
value
is
34
+
4g-cm
on
the
supply
side.
lf
the
mean
value
exceeds
38g-cm
adjust
the
value
to
34g-cm
by
adjusting
the
location
of
the
spring
(A)
in
the
direction
of
arrow
@as
shown
in
Fig.
4-6.
If
the
pointer
mean
value
is
much
less
than
30g-cm,
adjust
it
to
34g-cm
by
adjusting
the
location
of
the
spring
(A)
in
the
direction
of
arrow
(6).
Note:
The
deviation
of
back
tension
value
is
not
specified.
However,
if
it
fluctuates
by
more
than
5g-cm
after
a
stabilizing
period,
then
a
problem
exists
in
one
of
the
associated
parts.
Check and repair as required.
Check
that
no
skew
distortion
is
observed
during
playback.
Back Tension meter

4-7
Positioning
of
Gears
and
their
Installation
Sequence
A.
Setthe
gears
so
the
positioning
bore
holes
both
for
CAM-GEAR-M
and
main
plate
line
up
with
each
other
(see
Fig.
4-8(B)),
confirm
that
the
UNIT-ARM-MAIN
pin
on
the
front
side
of
deck
fits,
in
the
2
mm
slot
of
CAM-GEAR-M,
and
the
LEVER-AP
pin
shall
be
fits,
in
the
3mm
slot
(see
Fig.
4-7(A)).
B.
Set
ARM-LOAD
pin
so
it
fits
in
the
slot
of
CAM-GEAR-M
as
shown
in
Fig.
4-7(B).
C.
Fix
CP-BRAKE
pin
so
as
to
be
held
outside
of
CAM-GEAR-M.
Fig. 4-7(A)
D.
Install
ARM-LOAD-T,
refer
to
Fig.
4-7(B).
E.
Install
GEAR-T-L
so
it
aligns
with
the
positioning
hole
of
ARM-LOAD-T.
F.
Install
ARM-LOAD-S
so
the
hole
lines
up
with
the
positioning
hole
of
ARM-LOAD-T.
G.
Install
CAM-TENS
so
the
positioning
hole
lines
up
with
the
positioning
hole
of
ARM-LOAD,
etc.
H.
Install
Link-B
so
the
pin
to
inside
the
slot
of
CAM-GEAR-M
as
shown
in
Fig.
4-7(B).
|,
Install
GRIP-RINGS,
at
8
locations.
Positioning hole
Positioning hole
Positioning
hole
Fig. 4-7(B)
17
4-8
Mode
Switch
Attachment
and
Adjustment
Note:
When
adjusting
or
repairing
the
mode
switch
ensure
that
the
VCR
is
turned
off
in
the
“STOP”
mode.
Prior
to
adjustment,
it
should
be
confirmed
that
the
cassette
housing
is
in
the
status
of
cassette-in.
(STOP mode)
A.
Align
both
Matching
marks
on
the
mode
switch,
as
shown
in
Fig.
4-8(A).
B.
The
continuity
of
each
of
the
pins
should
be
check
to
ground
with
an
ohmmeter
by
connect-
ing
its
red
lead
to
GND,
and
black
lead
to
each
specific
pin
in
sequence.
Rotate
the
gear
so
the
continuity
conforms
with
the
that
given
in
Fig.
4-8(A).
Note:
The
ohmmeter
should
be
used
at
a
high
range
(X1000
or
higher)
Checking
with
x1
range
allows
current
of
over
40mA
to
flow
and
damage
could
result
(Mode
SW
Position
in
STOP
mode)
Matching mark
Po short
P, short
P2 open
P3 short
Fig. 4-8(A)
C.
Set
the
CAM-GEAR-M
so
the
positioning
hole
in
the
gear
lines
up
with
the
positioning
hole
in
the
main
plate,
as
shown
in
Fig.
4-8(B).
Mode switch fixing hole
Matching mark
CAM-GEARM
Positioning hole
Fig. 4-8(B)
D.
Secure
the
mode
switch
to
deck,
taking
care
that
the
gears
do
not
rotate.
E.
Repeat
the
continuity
test
given
in
lem
B,
if
any
deviation
is
found
after
the
mode
switch
is
mounted
remove
the
mode
switch
and
repeat
the
procedures
given
in
Items
@
~
©,
until
correct
continuity
is
achieved.

4-9
Half
Loading
Unit
Adjustment
4-9-1
Replacement
of
Half
loading
Unit
Remove
each
parts
in
the
following
order.
Top
cover
CORA
<
|e
Audio/Control
Head
2
oN
Seep
.
Ge:
(REAR
SIDE)
Screw@
GEARHL
Oe
¥
1). 50
a
Taper Nut
Front Loading Unit
Half
Loading
Unit
(Set
Screws
©,
©
and
©
are
shown
in
Fig.
4-9(A).
For
installation
of
the
parts
install
in
reverse
order
and
after
the
installation
of
Front
Loading
Unit
@
execute
the
adjustment
of
the
half
loading
gear
position
(See
4-9-2).
©OOOOO
Fig.
4-9(A)
(FRONT
SIDE)
Half
Loading
Unit
4-9-2
Adjustment
of
Half
Loading
Gear
Position
A.
Insert
a
dummy
cassette
in
the
cassette
hous-
ing
(at
this
time
the
recorder
will
go
into
the
PLAY
mode),
then
set
the
STOP
mode.
(At
this
time
the
half
loading
pole
moves
nearly
to
the
audio/control
head.)
B.
Disconnect
the
power
source
plug.
C.
Remove
the
set
screw
©
in
the
half
loading
unit
and
loosen
the
set
screws
©
and
©
(see
Fig.
4-9(A)).
Slide
the
half
loading
unit
in
the
direc-
tion
of
the
arrow@
<<
toalign
the
three holes
Fig. 4-9(B)
4-9-3
Adjustment
of
Half
Loading
Pole
Position
Adjust
the
position
of
the
half
loading
pole
after
interchangeability
and
A/C
head
adjustment
is
made.
A.
Disconnect
the
power
supply
plug
with
the
B,
C
and
D
in
the
half
loading
gear
to
the
position
shown
in
Fig.
4-9(B).
transport
in
the
fast
forward
mode
or
the
rewind
mode.
Loosen
the
set
screw
®
so
that
PLATE-HL-1
D.
Slide
the
half
loading
unit
in
the
direction
of
the
arrow
@)
©
and
secure
in
this
position
with
can
be
moved.
screws
©,
©
and
©.
Adjust
the
half
loading
Adjust
the
taper
screw
®
so
that
the
gap
pole
position
according
to
4-9-3
befor
perform-
between
the
half
loading
pole
and
AE-HEAD
ing
interchangeability
and
A/C
Head
adjust:
shall
be
0.45
+
0.15
mm
at
the
top
of
the
pole.
ments
and
secure
it
with
screw
for
the
(Fig.
4-9(C))
|
.
present.
.
Tighten
the
set
screw
@®).
After
tightening,
E.
Connect
the
power
source
plug
and
eject
the
check
again
if
the
gap
is
0.45
+
0.15
mm.
If
not,
dummy
cassette.
loosen
the
set
screw
and
adjust
the
gap
F.
After
performing
interchangeability
and
audio/
again.
control
head
adjustments,
readjust
the
half
loading
pole
position.
On
completion
of
adjustment,
lock
the
taper
screw
@)
and
the
set
screw
®
witha
locking
compound.
0.45 + 0.15
at the top
of pole
AE-HEAD
Taper Screw @ Set Screw
PLATE-HL-2
\
\
PLATE-HL-1
Half Loading Pole
Fig. 4-9(C)
18