Sharp 14VT10X1 User manual

SHARP
SERVICE MANUAL
S81G314VT10X1
m VIDEO TV
i
MODEL ‘I 4v 70x1
In the interests of user-safety (Required by safety regulations
in some countries) the set should be restored to its original con-
dition and only parts identical to those specified should be used.
CONTENTS
\
. SPECIFICATIONS ............................................................
2
. IMPORTANT SERVICE NOTES ................................................ 3
. DISASSEMBLYANDREASSEMBLY ............................................ 4
. FUNCTION OF MAJOR MECHANICAL PARTS ................................... 6
.
ADJUSTMENT, REPLACEMENTANDASSEMBLY OF MECHANICAL UNITS
.........
B
. ADJUSTMENT OF THE ELECTRICAL CIRCUITRY ................................ 34
l TROUBLESHOOTINGGUIDE
.................................................
49
.BLOCKDIAGRAM ..........................................................
69
l SIGNAL FLOW SYMBOLS AT A GLANCE .......................................
go
.WAVEFORMS .............................................................
91
l OVERALLDIAGRAM ........................................................ 95
. SCHEMATICDIAGRAMS ..................................................... 97
.WlRlNGSlDEPWBs .........................................................
115
l REPLACEMENT ELECTRICAL PARTS LIST .......................................
121
. EXPLODEDVIEWS ..........................................................
137
. PACKINGOFTHESET .......................................................
141
1
SHARP CORPORATION

DISASSEMBLY AND REASSEMBLY
1.
2.
3.
4.
5.
6.
7.
8.
9.
Remove the seven back cabinet fastening
screws 0.
Remove the one wire fastening screw 8.
Remove the one wire fastening screw @.
Remove the three VCR’s power unit fastening
screws @.
Remove the six VCR fastening screws 0 and
remove the VCR with the VCR’s operation.
Remove the CRT’s second anode cap @ from
the CRT.
Remove the “L2” lead wire @ from the CRT
socket unit @I.
Remove the CRTsocket unit @I.
Remove the TV mother unit with the frame
from the front cabinet.
10.
11.
12.
13.
14.
15.
16.
Remove the five TV mother unit fastening
screws 0 from the frame.
Remove the two speaker holder fastening
screws 0 and remove the holder.
Remove the speaker 0.
Remove the control unit fastening screw @
and remove the control unit from the front
cabinet.
Remove the two control unit fastening
screws @ .
Removethe one control unit fastening screw
0.
Remove the four CRT fastening screws 0.

DISASSEMBLY AND REASSEMBLY OF THE VCR SECTION
1. Remove the eight VCR holder fastening screws
a.
2. Remove the four upper cabinet fastening
screws 8.
3. Remove the seven bottom plate fastening
screws Q.
4. Remove the four cassette housing fastening
screws @.
5. Remove the five main PWB fastening screws @.
6. Remove the two head amp fastening screws @.
7. Remove the four mechanism chassis fastening
screws @.
8. Release the seven operation panel fastening
clips @ and remove the operation upper panel.
9. Remove the six operation holder fastening
screws @.
The VCR power unit removal
is described in the previous

FUNCTION OF MAJOR MECHANICAL PARTS (TOP VIEW)
pole base ass’y
AHC (fwtomatic headcleaner)
($) Cam stitch
\ @A/C head ass’y
x)
23 Dew sensor
Full erase head ass’y
Supply pole base
ass’y
Tension arm ass’
Loadi ng
motor
Relay
shifter lever
I
au- -/I
(14) Caostan D.D.motor
\ \ @Half-loading lever
No.
Function
No. Function
1.
Full erase head ass’y
13.
Erase the whole records on the tape in the recording Reverse guide
mode. Pulls out the tape in the video search rewind mode,
and controls the tape drive train height with the upper
3.
Tension arm ass’y
and lower guides.
Detects the tension of tape while running, and brakes
the supply reel disk via the tension band.
15. Relay shifter lever
Transmits the operation of the master cam to the
4.
Brake shifter brake shifter, and operates the reverse guide.
Set-the position of brake or the like in accordance with
the modes such as stop and playback.
16. Pinch roller lever ass’y
5. Back tension lever Press-fits the tape to the capstan during tape running.
Bakes the supply reel disk to a certain degree to The right protrusion switches the clutch of the cassette
prevent tape slackening during “half-loading”,housing control assembly in “tape eject”, and makes
“loading” and “shifting from playback to video search the mechanism
ejectthe tape.
rewind”.17.Master cam
7.
Main supply brake lever Turns clockwise during loading, and counterclockwise
Brakes the supply reel disk to prevent tape slackening during unloading, and moves the shifter or the like in
when the unit is stopped in fast forward or rewind accordance with each mode.
mode.
18.
9.
Main take-up brake lever Loading motor
A motive power which drives the mechanism. It
Brakes the take-up reel disk to prevent tape slackening
when the unit is stopped in fast forward or rewind transmits the power to the master cam and cassette
mode. housing control assembly via the belt.
10.
Half-loading lever
19. Cam switch
Bring the tape in contact with the A/C head, putting it Rotates synchronously with the master cam, and
in half-loading state in the fast forward or rewind detects the position of each mode by means of the
mode. internal switch
11.
Video search brake lever
23. Dew sensor
It is in contact with the take-up reel disk normally, and An element which detects condensation inside the
brakes itto a certain degree. It applies larger brake in unit. This element is activated, when it senses
the videosearch rewind mode. condensation, to interrupt the mechanism.
6
rer

FUNCTION OF MAJOR MECHANICAL PARTS (BOmOM VIEW)
Relay gear drive lever @
@Take-up loading gear
Slow brake lever
Loading relay gear 2
o-
Capstan D.D.motor 3
0
Reel belt @-
Brake solenoid 5
0
D
IO Supply loading gear
-4
8 AuxiliaFy fast forward
brake lever
d
6 Reel pulley
IlO.
Function No.
Function
1. Slow brake lever
7.
Reelsensor
Gets in contact with the capstan D.D. motor linking to An element which sheds the light onto the reflection
the master cam in the slow still mode, and brakes it to a plate affixed to the bottom side of the reel disk, and
certain degree.
detects the rotation of the reel disk through receiving
the reflected light.
3.
Capstan D.D. motor
A motive power which runs the tape. It transmits the
power via the reel belt.
8.
Auxiliary fast forward brake lever
Brakes the supply reel disk to a certain degree in the
fast forward and rewind modes. ’
4. Reel belt
Transmits the powerto run the tape to the reel pulley.
9. Take-up loading gear
Shifts the take-up pole base and guide roller via the
loading relay gear, and applies the tape around the
drum assembly, as well as transmits the power to the
supply loading gear.
5.
Brake solenoid
10.
Supply loading gear
Adsorbs and holds the brake shifter in the fast forward Shifts the supply pole base and guide roller via the
and rewind modes, and releases it in the stop mode. take-up loading gear, and applies the tape around the
drum assembly.
6.
Reel pulley
11. Relay gear drove lever
Transmits the power of the capstan D.D. motor to the Transmits the movement of the master cam to the
reel disk via the reel idler. take-up loading gear via the loading relay gear.
7

ADJUSTMENT, REPLACEMENT AND ASSEMBLY
OF MECHANICAL UNITS
Here we will describe a relatively simple service
work in the field, not referring to the more
complicated repairs which would require the use of
special equipment and tools (drum assembly
replacement, for example).
We are sure that the easy-to-handle tools listed
below would be more than handy for periodical
maintenance to keen the machine in its oriainal
working condition.
TOOLS NECESSARY FOR ADJUSTING THE MECHANICAL UNITS
The following tools are required for proper service and satisfactory repair.
0.
Jig Item Configuration
I
Remarks
These Jigs are used for checking and
adjusting the reel disk height
c
AK Head Tilt Adjusting Jig This Jig is used for setting the
A/C
These Jigs are used for checking and
adjusting the torque of take-up and
5
Gauge Head JiGTH0006
AW
This cassette torque meter is used
6
Cassette Torque Meter JiGVHT-063 C2
Q
%
for checking and adjusting the
torque of take-up for measuring
tape back tension.
Tension Gauge (3009)
JiGSG0300 BFThere are two Gauges used for the
7
Tens& Gauge (2.0kg)
JiGSG2000 BS
*.okg.
tensron measurements, 300 g and
Hex Wrench (0.9mm) JiGHW0009 AE
8
Hex Wrench (1.2mm)
6
These Jigs are used for loosening or
JiGHWOO12 AE tightening special hexagon type
screws.
Hex Wrench (1.5mm) JiGHWOO15 AE
Alignment Tape (PAL) VROCPSV CD
9
These tapes are especially used for
Alignment Tape (NTSC) VROATSV CDelectrical fine adjustment.
0
Drum Replacing Jig JiGDT-0001 BGThis is used for replacement of the
VCR’s upper drum.
8

-
0.
1
-
2
3
14
Torque Driver
15
Box Driver
16
17
Jig Item
Part No.
rension Gauge Adapter
JiGADP003
jpecial Bladed Screwdriver
JiGDRiVERH-4
Tension Band and Plate
9djusting Jig
Retaining Guide Height
Adjusting Jig
Reverse Guide Height
Adjusting Jig
JiGDRiVER-
JiGTDl200
JiGDRiVER 10-7
JiGDRiVER 10-4
JiGGH-F18
JiGRVGH-F18
C
-
:odc
-
BK
-
AP
-
BM
-
CB
-
AS
-
AV
-
BU
-
BU
-
Configuration
;“.:;
c
Remarks
rhis Jig is used with the tension
gauge. Rotary Transformer
Clearance Adjusting Jig.
This Screwdriver is used for
adjusting the guide roller height.
This Jig is used for adjusting the
tension band and tension plate.
This is used to screw down resin-
made parts: the specified torque is 5
kg.
This Jig is used for height
adjustment of the PJC head and X-
position.
This Jig is used for height
adjustment of the retaining guide.
This jig is used for height
adjustment of the retaining guide.
This Jig is used for height
adjustment of the reverse guide.
9

MECHANICAL PARTS REQUIRING PERIODICAL INSPECTION
Use the following table as a guide to maintain the mechanical parts in good operating condition.
inner hole and shaft)
Loadfng Motor
Automatic Head Cleaner
Reel block*
-4
*See the table below for servicing the reel block parts.
Possible symptom encountered Remarks
-atera noises
-lead occasionally blocked
Door S/N ratio, no colour
Door colour, beating
Sound toosmall or distorted
No tape running, uneven colour
No tape running, tape slack
Lateral image swing
Cassette not loaded or unloaded
See the chart below
Abnormal rotation or
significant vibration
requires replacement
Clean with pure high
quality isopropyl alcohol.
Clean tape contact part
with the specified cleaning
liauid.
Clean tape contact &ea
with the specified cleaning
liquid.
Clean rubber and rubber
contact area with the
specified cleaning liquid.
Replace the roller of the
cleaner when it wears
down. Just change the
video head cleaner arm
assembly for new one.
Supply/take-up reel disks on
no 0 n No tape running, tape slack Clean
with pure htgh
quality Isopropyl alcohol.
Vtdeo search brake lever
0
Idler gear ass’y 0
Notape running
Reel Pulley onno on
Maln supply/take-up brake levers 0
Tapeslack
NOTE: 0: Part replacement.
cl: Cleaning (For cleaning, use a lint-free cloth dampened with pure isopropyl alcohol).
A: Oil refilling (The indicated point should be lubricated with high quality spindle oil every
1000 hrs).
If the reading is out of the specified value, clean or replace the part.
10

R,EMOVAL AND REASSEMBLY OF 5.
CASSETTE HOUSING CONTROL ASSEMBLY
0
1.
2.
3.
Removal
Set the cassette ejected condition in the cassette
eject mode.
6.
Unplug the recorder from the main source.
Follow the procedures below in the specified
order.
a) Remove the cassette loading belt 0.
b) Disconnect the FFC (full Flat Cable) 8.
c) Remove the cassette housing installation
Place the unit in the eject mode in removal or
reassembly of the cassette housing control
assembly.
Load the cassette once onto the cassette housing
control assembly after reassembly. (If the
cassette housing control assembly normally
operates after this, the phases of mechanism and
the cassette controller are accurately adjusted
after ejection.)
screws 0.
d) Slide and pull out the cassette housing control
MECHANICAL OPERATION CHECK
WITHOUT CASSElTE
assembly upward @I.
When power is on, the general operations of the
~-I-
/==h
- _
Q
3 Cassette housing
setscrew
mechanism can be checked without a cassette.
Note the following points.
1. Check video search rewind and rewind, rotating
the take-up reel disk @ by hand (in either
!rse direction). If it is not rotated,
* works to shift the’Lmechanism to
C1I.c G,\-LC ,,,““d.
2. When the stop button is pressed, the mechanism
does not stop at a normal stop position. It shifts
to the eject mode and stops.
3. When the stop button is pressed in the playback,
video search rewind, and video search forward
modes, the supply reel disk 0 keeps on rotating
for several seconds for elimination of tape slack
in the course of shifting to the eject mode. In
such a case, rotate the take-up reel disk @
somewhat by hand, and the supply reel disk 0
stops, which can reduce the working time.
Insert the tab of
the cassette hosing
REpLAC~liACil’ fiC \Il,h”l” \“,,,rrl
, E IVI c IY I u r
vv u n WI
VvnrcL
control assembly to
ASSEMB LY
the mechanism chassis.
-.
Figure 1-l.
0 Reassembly
1. Before installation of the cassette housing
control assembly, place the unit in the stop mode
with the power on, then unplug the power cord.
(The main body is placed in the eject mode.)
2. Follow the procedures for removal in the reverse
order.
Notes:
1. Be sure to unplug the power cord in removal and
reassembly.
2. Keep the cassette loading belt free from grease.
In case of its adhesion, clean the belt.
3. In using a magnet screw driver, be sure to keep it
away from the A/C head, FE (Full Erase) head, or
the drum.
4. In removal and reassembly, take care not to hit
the cassette housing control assembly or tools
against the guide pin, drum, or the like
thereabout.
Cassette housing
Cassette housing frame (R)
Figure l-2.
11

0 Removal
1. Unsolder the cassette switch connectors (No. 16,
17) from the stat-t sensor PWB.
r/7
/Start sensor PWB
5. Place the slider pin just above the worm wheel
(Figure l-7). (The retainer of the slider is locked
at two positions hen. So unlock it as in the
Figure l-8.)
6. Pull out the worm wheel assembly toward you
pressing the switch lever upward. (Figure l-7)
Start sensor
fixing hook
Cassete switch
connector
Figurer l-3.
PWB
2. Lift the start sensor PWB pressing the two start
sensor PWB fixing hooks inward.
-Qqd
Start sensor PWB
Start sensor PWB fixing hook
Figure l-4.
3. Unscrew one B tight screw to detach the worm
bracket.
Note: The worm shaft bearing can easily come
out of position. So be careful not to lose
it.
-Worm wheel ass’y
Figure l-5.
bracket
4. Remove the worm shaft assembly, pulley, and
cassette loading belt all from the cassette
housing frame (R).
Worm shaft ass’y
Worm wheel ass’y
-Cassette
frame (R)
hosing
-s
witc :h lever
Cut washer
Figure l-7.
_ Slider Retainer opening
(Also provided on the IL) side
of cassette housing frame)
Cassette housing
rSlider
--Id
@
Press.
59
i,
Retainer
t
i
Cassette housing frame
(R) (Ll side
Figure 1-8.
l Reassembly
1. Turn the phase gear clockwise until the slider
comes to a halt in the cassette insertion
direction. (See the Figure l-9.)
2. Insert the set up worm wheel gear assembly into
the cassette housing frame (R), matching the
mark on the phase gear with the mark on the
worm wheel gear. Detach the cut washer on the
phase gear assembly and the phase gear for
easier installation of worm wheel assembly.
Note: Make sure that the slider pin is in the
groove of the drive gear arm.
Figure l-6.
12

\
5. Tighten one B tight screw.
Drive gear arm
tight screw (no
Note: Do not over-tighten the B
more than 5.0 t 0.5 kg.cm), because the
lower threads of the screw hole at the
resin-made boss can be broken.
6. Place the start sensor PWB on the cassette
housing frame (R).
Note: Check that the switch connectors (No. 16,
17) are in the cassette switch mounting
hole.
7. Finally resolder the cassette switch connector to
the start sensor PWB.
(4
b)
REASSEMBLY OF DRIVE GEAR
Figure l-9.
Worm wheel
3. install the pulley and the cassette loading belt on
the worm shaft assembly. Couple the clutch to Drive gear spring lR)
the clutch lever. And mount them together in
the cassette housing frame (R).
Note: Keep in mind that the clutch switching
lever should be in the correct position.
The mechanism might malfunction if the
lever is slightly out of position. (See page
14.)
Cassette housing frame Ft) Cassette loading belt
\
Pullev 7
. .,
\
Clutch 7
worm shaft ass.“-. 1
c
Cassette
‘housing
frame (R)
shaft bearing
Figure l-10.
4. Attach the worm bracket to the worm shaft
assembly. Place them onto the boss on the
cassette housing frame (R).
Note: Inset-t 0 before screwing into 8 and 0.
B tight
ssette housing frame (RI
Worm bracket Switch lever
Cassette housing frame (R) boss
Drive gear arm
L Drive gear arm
F
Drive oea%
w
(4
Drive oear
Reciprocating spring
#-
Drive gear (RI
spring shaft
(Drive gear bottom view)
spring (RI
LDrive gear arm
b)
Figure 1-12.
Pass the tip of the drive gear spring (R) 0
through the square hole of the drive gear (R) to
hook the spring in position.
Hook one end 0 of the reciprocating spring to
the catch of the drive gear(R).
Hook the other end Q of the reciprocating
spring to the catch of the worm wheel.
insert the pillar @ of the drive gear (R) into the
square hole of the worm wheel. Turn the worm
wheel somewhat counterclockwise for insertion
of the worm wheel to the drive gear (R), because
the reciprocating spring is at work.
Figure l-11.
13

REPLACEMENT OF CASSETTE LOADING
BELT
-
Worm shaft ass’y
t sensor PWB
Worm bracket
Figure 1-13.
1. Remove the start sensor PWB 0 and worm
’ bracket Q from the cassette housing frame(R).
2. Remove the worm shaft assembly 8.
3. Replace the cassette loading belt @ with a new
one.
Notes:
Do not overtighten the B tight screw which holds
the worm bracket in position. The specified
torque is 5.0 + 0.5 kg.cm.
Make sure that the cassette loading belt is free
from grease. If stained with grease, clean the
belt with the cleaning liquid.
Perform checking of the clutch switch lever for
proper action.
CHECKING THE CLUTCH SWITCH LEVER
Clutch lock lever
l Checking
Rib of cassette housmg frame iK1
Place the mechanism in the cassette eject mode
when removing and attaching the cassette housing
from and to the mechanism chassis.
Make sureenough that each part in the cassette
housing such as the clutch switch lever is in
position If not, it causes malfunction.
Note :
Figure 1-14 shows the position of each part in the
cassette eject mode.
Figure l-16.
.~
Shift the slider by turning the coupling in the
arrow direction (clockwise) until the slider pin is
at the bottom of the slider groove as shown in
the Figure l-16. (The loading mode)
Note: Note that the slider is equipped with a
lock mechanism. Unlock the locks on
cassette dousing frame (L) and (R) side
before shifting the slider.
When the position is set as shown in the Figure l-
16, push the clutch release lever in the direction
of the arrow by hand until the clutch lock lever
becomes tightly locked by the rib of the cassette
housing frame (R).
Then turn the coupling counterclockwise until
the slider reaches the cassette insertion opening
and the reciprocating spring is activated.
Note: There is no need to unlock the slider when
shifting the slider to the cassette insertion
opening. Just keep shifting the slider.
Swtch level
Clutch release
Rib 2’
‘i
f=Ilb of cassktre ‘-Clutch lock lever
Drove gear houslng frame (RI
1. First make sure that the tip of the switch lever is
held at the rib of the drive gear (R).
2. Check that the rib of the cassette housing frame
(R) and the concavity of the clutch lock lever are
engaged.
3. Finally be sure that the relationship between the
clutch lever and the clutch, as well as between
the clutch and the pulley, are correct as in the
Figure l-l 5.
Pulley
Check that the clutch is engaged
wtth the pulley through the coupling.
Figure 1-15.
0 Resetting
Take the following steps to reset the clutch if it is
unlocked or if the switch lever and the clutch lock
lever are unlocked.
lever
se lever
Figure l-14
14

REPLACEMENT OF LOCK RELEASE LEVER
0
1.
2.
Removal
Place the slider in the cassette down position.
(Turn the coupling on the worm shaft clockwise
until the slider is in the cassette down position.)
Note: Before shifting, unlock the slider.
Slightly widen the cassette housing frames (R)
and (L) to unhook the slider holders (R) and (L) of
the slider assembly off the grooves of the
cassette housing frames.
(4
Cassette housing
frame (RI
Cassette houslng
Slider holder (RI
Slider holder (Li
(b)
Figure 1-17.
3. Lift the slider holder (R) upward about 2mm off
the slider by pressing two catches with a thin tip
screw driver. Take care not to damage the
catches.
/Slide lock catch
Slider holder V?
Slide it upward
about 2 mm.
Lock release lever
Lock release lever spring
Figure l-18.
4.
l
1.
2.
3.
4.
5.
Remove the lock release lever
holder(R) from the slider
Reassembly
I. _I
Follow the steps for removal In tne reverse order.
(See Figures 1-17 and l-18.)
Attach the lock release lever to the slider holder
(R).
Slide the slider holder (RI downward so that the
two catches of the slider holder (R) fit the
opening of the slider.
Slightly widen the cassette housing frames, and
set the pins of slider holders (R) and (L) into the
grooves of the cassette housing frames.
Note: Check if the pins of the slider holders (R)
and (L) fit the grooves of the cassette
housing frames, and if the drive gear arm
is sufficiently engaged with the slider
holders.
Turn the coupling counterclockwise until the
slider is at the cassette insertion opening.
TO RUN A TAPE WITHOUT THE CASSETTE
HOUSING CONTROLASSEMBLY
1. Plug in the power cord.
2. Turn on the power switch.
3. Open the lid 0 of a cassette tape by hand.
4. Hold the lid with a pair of vinyl tapes 8.
5. Set the cassette tape in the mechanism chassis.
6. Weight the cassette tape with a weight @ to
prevent float.
7. Perform running test.
Cassette tape
Wetght to prevent i,, )J
here
float 1500 gi
. . .y .,T
, >
.1
Mechanism chassis
Note: The weight should not
be more than 500 g.
Figure l-19.
15

REPLACEMENT AND HEIGHT CHECKING
AND ADJUSTMENT OF REEL DISKS
1.
2.
3.
0
1.
2.
3.
4.
Remove the cassette housing control assembly.
Set the mechanism in the playback mode with no
cassette tape in place. Unplug the power cord.
Set the idler gear in the center (neutral).
Removal (Supply reel disk)
Remove the tension band 0. (Take care not to
deform it.)
Unscrew the screw @ and remove the supply reel
retainer assembly (6>.
Release the supply reel disk catch and back
tension lever 0.
Pull the supply reel disk upward.
Notes :
1. Take care not to deform the tension band.
2. Check and adjust the tension pole position. (See
page 2 1.)
3. Be careful not to damage the gear and the idler
gear on the supply reel disk.
4. Press the tension band in the direction of the
arrow for removal (see Figure 1-20(b)).
l Removal (Take-up reel disk)
1. Unscrew the screw cc/ and remove the take-up
reel retainer.
2. Release the take-up reel disk catch 0.
3. Pull the take-up reel disk Q upward.
-
Take-up
reel disk
Take-up reel ratamer
Figure l-21.
enston ever
Note :
When the tension band is pressed in the
direction of the arrow for removal, the
catch is hard to be deformed.
t
v
0
1.
2.
3.
4.
5.
Reassembly (Supply reel disk)
Clean the reel disk shaft 0 and apply oil to it.
Release the supply reel disk catch 8 and back
tension lever 0.
Install a new supply reel disk @ onto the shaft.
Replace the tension band @ around the supply
reel disk, and insert it to the hole of the tension
arm.
Replace the supply reel retainer assembly @ in
place, and tighten up the screw (4.
Notes :
1. Take enough care not to deform the tension
band during installation of the supply reel disk.
2. Be careful not to damage the supply reel disk
aear, back tension lever, catch, or the like with
Fool;.
ension band
&m
Supply reel disk
.-c
/ 0
rzl
0 Screw
Q
4
w
L I-
Supply reel
T’
retamer ass’y
S‘;bply reel
d!sk catch
b)
Figure l-20.
Figure 1-22
16

l Reassembly (Take-up reel disk)
1. Clean the reel disk shaft @ and apply oil to it.
2. Release the take-up reel catch 8 and video
search brake lever a.
3. Install a new take-up reel disk @I onto the shaft.
4. Replace the take-up reel retainer @ in position
and tighten up the screw 0.
Note :
Take care not to damage the video search brake
Clean the reel disk shaft well.
and apply 011 to It.
lever.
Video search
PJ brake lever
Apply a thin ttp drwer to the arrow posItton In
releasing for easier setting of the take-up reel dtsk
Figure l-23.
*After reassembly, check the video search rewind
back tension (see page 20), and check the brake
torque (see page 22).
l Height checking and adjustment
Note:
Place the master plane onto the mechanism unit,
taking care not to hit the drum (see Figure l-24)
1. For height adjustment, press the reel disk with a
finger, and turn. it right and left with a
screwdriver (see Figure l-26 (a)).
Setting
/-
Master plane
Set the master plane releasmg
the reverse guide by a fmger.
Figure l-25.
2. Check that the reel disk is lower than part A but
higher than part B. If the height is not correct,
adjust the height adjusting screw (see Figure l-
26 (b)).
Note :
Whenever replacing the reel disk, perform the
height checking and adjustment.
(4
Slide It right and left.
and check contact wth
the reel disk.
Reel disk height
adlustIng 119
1
r _ &yg_im’+ ‘> .2
lO%O.Zmm
Reel disk Mechanism chassis
I
I
(b)
Figure l-26
Figure 1-24.
17

CHECKING AND ADJUSTMENT OF TAKE-UP
CHECKING AND ADJUSTMENT OFTAKE-UP
TORQUE IN FAST FORWARD MODE TORQUE
IN REWIND MODE
l Remove the cassette housing control assembly.
l
Remove the cassette housing control assembly.
0 Setting
l Setting
Set the scale to “0”
Torque gauge
+
Setting
ke-up reel disk
Figure l-27.
l Checking
Turn the torque gauge slowly
(one rotation every 2 to 3
seconds) by hand in the
take-up direction
700g.cm or more
The gauge is held a
its maximum value.
(Red mark)
Take-up dIrection
Figure l-28.
l Adjustment
1. If the take-up torque is outside the range, clean
the capstan D.D. motor pulley, reel belt and reel
pulley with cleaning liquid, then recheck the
torque.
2. If the take-up torque is still out of range, replace
the reel belt.
Notes :
1. Hold down the torque gauge so that it may not
fly off.
2. When checking the take-up torque, do not keep
the reel disk locked for a longer time.
Set the scale to
“0”
Torque gauge
Setting
+
Supply reel disk
Figure l-29.
l Checking
Turn the torque gauge slowly
(one rotation every 2 to 3
seconds) by band in the
take-up direction
700gfm or more
The gauge is held at-
its maximum value.
Figure l-30.
w
0 Adjustment
1. If the take-up torque is outside the range, clean
the capstan D.D. motor pulley, reel belt and reel
pulley with cleaning liquid, then recheck the
torque.
2. If the take-up torque is still out of range, replace
the reel belt.
Notes :
1. Hold down the torque gauge so that it may not
fly off.
2. When checking the take-up torque, do not keep
the reel disk locked for a longer time.
18

CHECKING AND ADJUSTMENT OF TAKE-UP CHECKING AND ADJUSTMENT OF TAKE-UP
TORQUE IN PLAYBACK MODE
TORQUE IN VIDEO SEARCH REWIND MODE
1.
2.
Remove the cassette housing control assembly.
Open the lid of the cassette torque meter, and
hold it with a pair of vinyl tapes.
Load a cassette torque meter Into the unit
9
Set value SP 95 ? 30g.cm
Figure 1-31.
Checking
&. The toraue fluctuates due to the rotational
Check that the torque is in the range of 95 f 30
g-cm.
~.
.~
deviation of the reel drive unit. Use the center of
the fluctuation as the value.
3. Place the unit in the SP record mode, and check
that the take-up torque is within the range.
l Remove the cassette housing control assembly.
Push the play button to place Push the video search rewmd
the unit I” the playback mode. button to place the unit in the
video search rewind mode.
Torque gauge
Place the torque gauge on the supply reel
disk, and turn it counterclockwlse very slowly
lone rotation every 2 to 3 seconds) and check
that the torque IS wlthln the set value
170+40 g’cm.
Supply reel disk x;;>
CzY
Figure l-32.
Note:
Set the torque gauge securely on the supply reel
disk. If it is not secure, the measurement will be
incorrect.
l Adjustment
If the take-up torque in video search rewind mode
is outside the range, replace the supply reel disk.
Note :
The torque fluctuates due to the rotational
deviation of the supply reel disk. Use the center of
the fluctuation at the value.
l Adjustment
If the take-up torque in the playback mode is
outside the range, replace the take-up reel disk.
Note: Weight the cassette torque meter to
prevent float.
19

CHECKING THE FAST FORWARD BACK CHECKING THE VIDEO SEARCH REWIND
TENSION BACK TENSION
l Remove the cassette housing control assembly.
@ Remove the cassette housing control assembly.
l Checking
l Checking
e :h’I *Torque gaug
‘I I\’
9
4
Place the unit in the
fast forward mode.
3
‘I I\’
4
Push the play button to place Push the video search rewind
the unit in the playback mode. button to place the unit in the
video search rewind mode.
Supply reel disk Torque gauge
Place the torque gauge on the supply
reek disk, and turn it clockwise very
slowly (one rotation every 2 to 3 seconds)
and check that the torque is within
152 5 g.cm
Place the torque gauge on the take-up reel
disk, and turn it couterclockwise very slowly
(one rotation every 2 to 3 seconds) and check
that the torque is within the set value
455 20 g.cm.
Note :
Take-up reel disk
kzh
u
Figure l-35.
Note :
Figure l-33.
Set the torque gauge securely on the supply reel
disk. If the torque gauge is not securely set on the
reel disk, measurement will‘be incorrect.
CHECKING THE REWIND BACK TENSION
l Remove the cassette housing control assembly.
l Checking
/
Place the unit In the
rewind mode.
Take-up reel disk
Note :
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 wlthin 152 5 g’cm.
Figure l-34.
Set the torque gauge securely on the take-up reel
disk. If it is not secure, the measurement will be
incorrect.
Set the torque gauge securely on the take-up reel
disk. If it is not secure, the measurement will be
incorrect.
CHECKING THE PINCH ROLLER PRESSURE
l Remove the cassette housing control assembly.
Push the play button to place the
unit In the playback mode.
Tension gauge
1 .aoo- 1,200 g
Capstan shaft
soon gauge adapter
Figure l-36.

1.
2.
3.
4.
Detach the pinch roller from the capstan shaft.
Set the tension gauge by hooking the tension
gauge adapter onto the pinch roller shaft.
Gradually release the pressure to allow the pinch
roller to touch the capstan shaft. When the
pinch roller just touches the capstan shaft, read
the indication on the gauge.
Check that the reading of the tension gauge is in
the range of 1000 to 1200 g.
CHECKING AND ADJUSTMENT OF TENSION
POLE POSITION
l Remove the cassette housing control assembly.
Vinyl tapes
* :& *
Place the unit I”
the record mode.
echanism chassts
(4
G
Guide roller B
utde roller A
Check the lef-t
Tenston band
and plate
adjusting 119
settlng hole
Video cassette tape (E-1 80)
(b)
Figure l-37.
l Checking
1. The guide rollers (A, B) operate to bring the tape
outside the cassette tape and simultaneously the
tension pole moves to the left, loading the tape.
At that time (loading completed), check the
position of the tension pole.
2. At the beginning of the tape (E-180), check that
the tension pole’s left side is aligned with the
supply impedance roller’s left side by sight.
3. Check that the end of the tape is neither curled
against the flange of the supply impedance
roller nor over it.
4. During the video search rewind mode with no
cassette tape in place, check that the supply
reel disk is free from the tension band.
l Position adjustment (record mode)
When the tension pole is at the right of the supply
impedance roller’s center:
Untighten the tightening screw, and shift the ten-
sion band adjustment bracket in the direction of
the arrow using a tension band and plate adjusting
jig until it is in the set value range (left side). Then
secure it with the tightening screw.
I
Supply impedance roller
Center Tension band Tension pole
SUPPlY
and plate
sung
I ensjon arm
Tenston band adjustment bracket
Figure l-38.
l Position adjustment (record mode)
When the tension pole is at the left of the supply
impedance roller’s center:
Untighten the tightening screw, and shift the ten-
sion band adjustment bracket in the direction of
the arrow using a tension band and plate adjusting
jig until it is in the set value range (left side). Then
secure it with the tightening screw.
I
Supply Impedance roller
TensIon pole
3e
adI1
Supply reel
/ -
Tenston band adjusrment bracket band
21
Figure 1-39.

CHECKING AND ADJUSTMENT OF RECORD
I PLAYBACK BACK TENSION
l Remove the cassette housing control assembly.
Open here
Cassette torque meter
Push the record button
/ to place the unit
m the record mode
Figure l-40.
chassis
1. Put a cassette torque meter into the unit.
2. Push the record button to place the unit in the
record mode.
3. Check that the back tension indicated by the
gauge is within the set range 31 to 36 g.cm.
Notes :
1. Make sure that the video cassette tape is over
the retaining guide.
2. Make sure that the tape is not slack nor
damaged at either end.
l Adjustment
1. If the reading of the cassette torque meter is less
than specified, move the tip of the tension spring
hook pIaYe toward the hole A.
2. If the reading of the cassette torque meter is
more than specified, move the tip of the tension
spring hook plate toward the hole 6.
* Put a thin screw driver (-) in the shaft hole, lean
it toward you, and turn it for easer shift of the
tension spring hook plate in the direction of A or
B.
/
LA
Tenston spring
Tension swng
hook plate
Tension spring hook plate
Figure 142. Not used.
CHECKING THE BRAKE TORQUE
l
Checking the brake torque at the supply side
Torque gauge
,-Supply reel disk
ti
--/
-5:’
Supply reel
disk
Adjust the Idler gear
in the center
Figure 1-41
Mechanism chassts
Figure 143.
22