Sharp VC-S2000HM User manual

1
VC-S2000HM
VIDEO CASSETTE RECORDER
SERVICE MANUAL
Page
1. SPECIFICATIONS................................................................................................................. 3
2. DISASSEMBLY AND REASSEMBLY ................................................................................... 4
3. FUNCTION OF MAJOR MECHANICAL PARTS................................................................... 7
4. ADJUSTMENT, REPLACEMENT AND ASSEMBLY OF MECHANICAL UNITS.................. 9
5. ELECTRICAL ADJUSTMENT ............................................................................................. 28
6. MECHANISM OPERATION FLOWCHART AND TROUBLESHOOTING GUIDE .............. 31
7. ELECTRICAL TROUBLESHOOTING ................................................................................. 37
8. BLOCK DIAGRAM............................................................................................................... 53
9. SCHEMATIC DIAGRAM AND PWB FOIL PATTERN......................................................... 63
10. REPLACEMENT PARTS LIST ............................................................................................ 81
11. EXPLODED VIEW OF MECHANICAL PARTS ................................................................... 92
12. PACKING OF THE SET ...................................................................................................... 96
SHARP CORPORATION
MODEL
Intheinterestsofuser-safety(Requiredbysafetyregulationsinsome
countries) the set should be restored to its original condition and only
parts identical to those specified be used.
VC-S2000HM
S80G3VC-S2000
CONTENTS

2
VC-S2000HM
PRECAUTIONS IN PART REPLACEMENT
When servicing the unit with power on, be careful to the section marked white all over.
This is the primary power circuit which is live.
Whencheckingthesoldering sideinthetapetravelmode,makesurefirstthatthetapehasbeenloadedandthenturnover
the PWB with due care to the primary power circuit.
Make readjustment, if needed after replacement of part, with the mechanism and its PWB in position in the main frame.
(1) Start and end sensors: Q701 and Q702
Insert the sensor’s projection deep into the upper hole of the holder. Referring to the PWB, fix the sensors tight
enough.
(2) Photocoupler: IC901 and IC902
Refer to the symbol on the PWB and the anode marking of the part.
(3) Cam switches A and B: D708 and D705.
Adjust the notch of the part to the white marker of the symbol on the PWB. Do not allow any looseness.
(4) Take-up and supply sensors: D711 and D712.
Be careful not to confuse the setting direction of the parts in reference to the symbols on the PWB. Do not allow any
looseness.

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VC-S2000HM
1. SPECIFICATIONS
Format: VHS PAL / S-VHS / S-VHS ET standard
Video recording system: Two rotary heads, helical scan system
Video signal: PAL colour and I signals, 625 lines
Recording/playing time: 240 min max. with SHARP E-240 tape (SP mode)
480 min max. with an E-240 tape (LP mode)
720 min max. with an E-240 tape (EP mode)
Tape width: 12.7mm
Tape speed: 23.39 mm/s (SP mode)
11.70 mm/s (LP mode)
7.8 mm/s (EP mode)
Antenna: 75 ohm unbalanced
Receiving channel: VHF Channel E2-E12, S1-S41
UHF Channel E21-E69
RF converter output signal: UHF Channel E21-E69 (Preset to CH E36)
Power requirement: AC220V ~ 240V, 50Hz
Power consumption: Approx. 19W
1.5W max. (at Low power mode)
Operating temperature: 5°C to 40°C
Storage temperature: –20°C to 55°C
Weight: Approx. 4.3 kg
Dimensions: 430 mm (W) x 300 mm (D) x 91.5 mm (H)
VIDEO
Input: 1.0 Vp-p, 75 ohm
Output: 1.0 Vp-p, 75 ohm
Horizontal resolution: 250 lines (SP mode)
AUDIO 0 dBs = 0.775 Vrms
Input: Line1: -3.8 dBs, 10k ohm
Line 2:-3.8 dBs, 10k ohm
Line 3:-3.8 dBs, 47k ohm
Output: Line1: -3.8 dBs, 1k ohm
Line 2:-3.8dBs, 1k ohm
Hi-Fi Dynamic Range: 90 dB TYP
Hi-Fi Wow and Flutter: 0.005%
Hi-Fi Frequency Responce: 20 Hz ~ 20 kHz
Accessories included: 75 ohm coaxial cable
Operation manual
Infrared remote control
Battery
Note: The antenna must correspond to the new standard DIN 45325
(IEC 169 - 2) for combined UHF/VHF antenna with 75 ohm connector.
Aspartofourpolicyofcontinuousimprovement,wereservethe
right to alter design and specifications without notice.

4
VC-S2000HM
2. DISASSEMBLY AND REASSEMBLY
2-1 DISASSEMBLY OF MAJOR BLOCKS
D
cb
a
c
b
a
B
C
A
C1
D
B
A
1
1
2
4
4
4
6
6
7
5
89
9
10
11
12
14
13
18
15
15
16
17
19
C1
3
3
C
TOP CABINET : Remove 4 screws 1.
FRONT PANEL : Remove2screws2and 7clips 3.
PWB HOLDER : Remove 3 screws 4.
OPERATION (L) : Take it out of connector 5, 3 clips
PWB 6and 2 clips 7.
OPERATION (R) : Remove 3 clips 9.
PWB
FUNCTION PWB : Remove 4 connectors 0
TERMINAL PWB : Remove 3 screws q, 1 screw w,
1 screw eand 2 connector r.
MECHANISM/ : Remove 2 screws t, 2 screws y,
MAIN PWB 2 screws u, and 1 hook i.
ANTENNA : Remove 1 screw o.
TERMINAL
COVER
TOP CABINET
FRONT PANEL
OPERATION (L)
PWB
OPERATION (R)
PWB
PWB HOLDER
FUNCTION PWB
TERMINAL PWB
MECHANISM
ANTENNA
TERMINAL
COVER

5
VC-S2000HM
1. Remove 1 screw 1from behind of the MAIN PWB.
Remove the FFC cable (AA,AD,AH) 2which con-
nects the PWB and the mechanism.
Take out vertically the mechanism so that it does not
damage the adjacent parts.
2-2 DISASSEMBLING THE MECHANISM/MAIN PWB ASSEMBLY
2. Removing the mechanism and cassette housing.
Remove2screws3fixingthecassettehousingtothe
mechanism, and remove the cassette housing.
1
2
3

6
VC-S2000HM
cassette housing. (Conditions: When mechanism and
PWB have been installed)
2. Mechanical initial setting
Feed the pulley feed gear of loading motor with screw
driver. After ascertaining the return to the initial set posi-
tion (*1) install the cassette housing in the specified
position.(Thismethodisappliedonlyforthemechanism.)
PARTS WHICH NEED PARTICULAR CARE
WheninstallingthemechanismchassisonthePWBunit,
take care so as to prevent deformation due to contact of
mechanism chassis with REC TIP SW.
Pulley feed gear
Screwdriver
Casecon
drive gear
Drive angle of
cassette housing
Tilt mark (*1)
INSTALLING THE CASSETTE HOUSING
Whenthecassettehousingisinstalledonthemechanism,
the initial setting is essential condition.
There are two initial setting methods, namely electrical
and mechanical.
1. Electrical initial setting
So as to perform initial setting of mechanism execute the
Step1ofInstallation of cassette housing. After ascertain-
ing the return to the initial setting position (*1) install the
2-3 CARES WHEN REASSEMBLING
INSTALLING THE MECHANISM ON PWB
Lower vertically the mechanism, paying attention to the
mechanism edge, and install the mechanism with due
care so that the parts are not damaged. So as to fix the
mechanismtothemainPWBinstalltwohousings.(Fitthe
antenna cover to one of them. For other, fix the vicinity of
loading motor and solder joint side of main PWB.) Con-
nect again the FFC cable (AA-MH, AD-ME, AH-MZ)
between the mechanism and the main PWB.
Rec Tip Switch
End Sensor
ALConnector
AE Connector
AC Connector
Start Sensor

7
VC-S2000HM
3. FUNCTION OF MAJOR MECHANICAL PARTS (TOP VIEW)
No. Function No. Function
1 Full erase head
2 Supply pole base ass’y
3 Tension arm ass’y
4 Idler wheel ass’y
5 Pinch drive lever ass’y
6 Supply reel disk
7 Supply main brake ass’y
8 Take-up main brake ass’y
9 Pinch drive cam
10 A/C Head ass’y
11 Reverse guide lever ass’y
12 Casecon drive gear
13 Take-up reel disk
14 Pinch roller lever ass’y
15 Drum ass’y
16 Loading motor
17 Drum motor
18 Take-up pole base ass’y
1715 10
11
5
9
14
12
8
16
13
4
6
2
7
3
1
181715 10
11
5
9
14
12
8
16
13
4
6
2
7
3
1
18

8
VC-S2000HM
FUNCTION OF MAJOR MECHANICAL PARTS (BOTTOM VIEW)
26
24
21
22
19
20
12
23
No. Function No. Function
19 Slow brake
20 Master cam
21 Capstan D.D. motor
22 Reel belt
23 Clutch lever
24 Limiter pulley ass'y
12 Casecon drive gear
26 Shifter

9
VC-S2000HM
4. ADJUSTMENT, REPLACEMENT AND ASSEMBLY OF MECHANICAL UNITS
The explanation given below relates to the on-site general service (field service) but it does not relates to the adjustment
and replacement which need high-grade equipment, jigs and skill. For example, the drum assembling, replacement and
adjustment service must be performed by the person who have finished the technical courses.
4-1 MECHANISM CONFIRMATION ADJUSTMENT JIG
So as to perform completely the mechanism adjustment prepare the following special jigs. So as to maintain the initial
performance of the machine the maintenance and check are necessary. Utmost care must be taken so that the tape is
not damaged. If adjustment needs any jig, be sure to use the required jig.
JiGTG1200 CN
JiGMP0001 BY
1. Torque Cassette Meter JiGVHT-063 CZ
No. Jig ltem Part No. Code Configuration Remarks
JiGTG0090 CM
3. Torque Gauge Head JiGTH0006 AW
5. JiGRH0002 BR
JiGSG2000 BS
JiGSG0300 BF
6.
7. JiGADP003 BK
2. Torque Gauge
Tension Gauge
These Jigs are used for checking
and adjusting the reel disk height.
Whenfixinganyparttothethreaded
hole using resin with screw, use the
jig. (Specified torque 5 kg)
Thiscassettetorquemeterisusedforcheck-
ing and adjusting the torque of take-up for
measuring tape back tension.
These Jigs are used for checking
and adjusting the torque of take-up
and supply reel disks.
Master Plane Jig and
Reel Disk Height
Adjusting Jig
Pinch pressing force
measuring jig
This Jig is used with the tension
gauge.Rotarytransformerclearance
adjusting jig.
There are two gauges used for the
tension measurements, 300 g and
2.0kg.
4. Torque Driver JiGTD1200 CB
9. JiGDRiVER11055 AR
Reverse guide height
adjusting box driver This Jig is used for height adjustment of the
reverse guide (for reverse guide height ad-
justment).
Guide roller height
adjustment drive This screwdriver is used for adjusting the
guide roller height.
For X value adjustment
X value adjustment
gear type screw driver
This Jig is used for height
adjustment of the reverse guide.
13. JiGRVGH-F18 BU
12. JiGDRiVER-6 BM
Reverse Guide Height
Adjusting Jig
11. JiGDRiVERH-4 AP
Video Audio Track
625 Monoscope 6kHz 35µm
625 Monoscope 6kHz
and and 49µm
Colour bar 1kHz
VROUBZFS
VROCPSV
10. Alignment Tape CK

10
VC-S2000HM
Video head cleaning procedure
1. Apply one drop of cleaning liquid to the cleaning paper with the baby oiler.
2. Gentlypress thecleaningpaper againstthevideo headtofix yourfinger,and movetheupper drumsothat eachhead
is passed to and from 5 times (do not move the cleaning paper).
3. Wipe with the dry cleaning paper.
Notes :
• Use the commercially available ethanol of Class 1 as
cleaning liquid.
• Since the video head may be damaged, do not move up
and down the cleaning paper.
• Whenever the video head is cleaned, replace the clean-
ing paper.
• Do not apply this procedure for the parts other than the
video head.
Parts Code Description Code
ZPAPRA56-001E Cleaning Paper AW
ZOiLR-02-24TE Babe Oiler (Spoit) AH
NOTE : Part replacement. : Cleaning : Apply grease
<Specified> Cleaning liquid Industrial ethyl alcohol
* This mechanism does not need electric adjustment with variable resistor. Check parts. If any deviation is found,
clean or replace parts.
Maintained
Parts Remarks
500
hrs. 1000 hrs. 1500 hrs. 2000 hrs. Possible symptom
encountered
Guide roller ass’y
Sup guide shaft
Reverse guide
Slant pole on pole base
Full erase head
A/C head
Upper and lower drum ass’y
Capstan D.D. motor
Pinch roller
Reel belt
Tension band ass’y
Loading motor
Idler ass’y
Limiter pulley
Supply/take-up main brake levers
AHC (Automatic Head Cleaner)
color and beating
Small sound or sound
distortion
Poor S/N ratio, no color
Poor flatness of the
envelope with alignment
tape
No tape running,
uneven color
No tape running, tape
slack
No tape running, tape
slack, no fast forward/
rewind motion
Lateral noises Head
occasionally blocked
Abnormal rotation or significant
vibration requires replacement.
Clean tape contact part with the
specified cleaning liquid.
Clean tape contact area 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 AHC roller
assembly for new one.
Screen swaying
Cassette not loaded or
unloaded
No tape running, tape
slack
Tape slack
MAINTENANCE CHECK ITEMS AND EXECUTION TIME
Perform the maintenance with the regular intervals as follows so as to maintain the quality of machine.
Gently press the cleaning paper to
fix with your finger, and rotate the
upper drum to clean.
Move to and from 5 times for each head.
(Do not move the cleaning paper.)
Rotate the upper drum
with one hand.

11
VC-S2000HM
Figure 4-1.
• Reassembly
1. Before installing the cassette housing control, short-
circuit TP801 provided at the center (when facing to the
main PWB), press the eject button. The casecon drive
gear turns and stops when the positioning mark ap-
pears. Engage two teeth of casecon drive gear with the
three teeth of casecon drive angle gear, and set on the
mechanism chassis as shown below.
Figure 4-2.
2. Install in the reverse order of removal.
Notes:
1. When fitting the S/E sensor holder to the cassette
controller frame L/R, take care.
2. Misengagementofteethofcasecondrivegearanddrive
anglegearcausesmalfunction.(Thecassettecannotbe
set, load and ejection are repeated).
3. Inthecasewhenyouusethemagnetscrewdriver,never
approach the magnet driver to the A/C head, FE head,
and drum.
4. When installing or removing, take care so that the
cassette housing control and tool do not contact the
guide pin or drum.
5. After installing the cassette housing control once per-
form cassette loading operation.
TO RUN A TAPE WITHOUT THE CASSETTE
HOUSING CONTROL ASSEMBLY
1. Remove the full-surface panel.
2. Short-circuit TP801.
3. Plug in the power cord.
4. Turn off the power switch.
(The pole bases move into U.L.position.)
5. Open the lid of a cassette tape by hand.
6. Hold the lid with two pieces of vinyl tape.
7. Set the cassette tape in the mechanism chassis.
8. Stabilize the cassette tape with a weight (500g) to
prevent floating.
9. Turn on the power switch.
10. Perform running test.
REMOVINGANDINSTALLINGTHECASSETTE
HOUSING
• Removal
1. In the cassette removing mode, remove the cassette.
2. Unplug the power cord.
3. Remove in the following numerical order.
a) Remove two screws 1.
b) Slide and pull up the cassette housing control.
1
Casecon
drive gear Casecon drive
angle gear
500g
Figure 4-3.
Mechanism chassis
Weighttoprevent
float (500g)
Note:
The weight should not be more than 500g.
To take out the cassette tape.
1. Turn off the power switch.
2. Take out the cassette tape.

12
VC-S2000HM
REEL DISK REPLACEMENT AND HEIGHT
CHECK
• Removal
1. Remove the cassette housing control assembly.
2. Pull the tension band out of the tension arm ass'y.
3. Remove the Supply/Take-up main brake ass'y.
4. Openthehookatthetopofthereeldisk,andremovethe
reel disk.
Note:
Take care so that the tension band ass'y and main brake
ass'y (especially soft brake) are not deformed.
4. Assemble the Supply main brake ass'y.
Notes:
1. When installing the reel disk, take due care so that the
tension band ass'y is not deformed and grease does no
adhere.
2. Donot damage the Supply mainbrakeass'y.Be careful
so that grease does not adhere to the brake surface.
• Reassembly (Take-up reel disk)
1. Clean the reel disk shaft and apply grease (SC-141) to
it.
2. Align the phase of the reel disk to that of the reel relay
gearandtoinstallanewtake-upreeldiskontotheshaft.
3. Check the reel disk height and reassemble the take-up
main brake ass'y.
Note:
1. Take care so that the Take-up main brake ass'y is not
damaged.Takecaresothatgreasedoesnotadherethe
brake surface.
2. After reassembly, check the video search rewind back
tension (see page 15), and check the brake torque (see
page 17).
• Height checking and adjustment
Note:
1. Set the master plane with due care so that it does not
contact the drum.
2. When putting the master plane, shift the reverse guide
alittleinthe loading direction.Caremustbetakensince
excessive shift results in damage.
Figure 4-6.
Note:
• Check that the reel disk is lower than part A but higher
than part B. If the height is not correct, readjust the reel
diskheightbychangingthepoly-sliderwasherunderthe
reel disk.
Figure 4-4.
Note:
When the tension band ass'y is pressed in the direction of
the arrow for removal, the catch is hard to be deformed.
Figure 4-5.
• Reassembly (Supply reel disk)
1. Clean the reel disk shaft and apply grease (SC-141) to
it.
2. Matchthephasesofreeldiskandreelrelaygear,andset
the new reel disk.
3. After checking the reel disk height, wind the tension
band ass'y around the reel disk, and insert into the hole
of tension arm ass'y.
Tension arm ass'y
Supply reel disk Take-up reel disk
Master plane
Reverse
guide
Position
pin
Take-up main brake ass'y
Supply reel disk
Cassette lock
release shaft
Take-up reel disk
Tension band ass'y
Supply main brake ass'y

13
VC-S2000HM
Note:
Wheneverreplacingthereeldisk,performtheheightcheck-
ing and adjustment.
Notes:
1. Hold the torque gauge by hand so that it is not moved.
2. Donotkeepthereeldiskinlockstate.Donotallowlong-
time measurement.
CHECKING AND ADJUSTMENT OF TAKE-UP
TORQUE IN REWIND MODE
• Remove the cassette housing control assembly.
• After short-circuiting TP801 provided at the center
(facing to the main PWB), plug in the power cord.
• Setting
1. Set a torque gauge to zero on the scale. Place it on the
supply reel disk.
2. Press the rewind button.
3. To calculate the remaining capacity, slowly rotate the
take-up reel disk, and then shift it into the rewind mode.
• Checking
1. Turn the torque gauge slowly (one rotation every 2 to 3
seconds) by hand in the CCW direction.
2. Makesurethatthe indication of torque gaugeisnotless
than 30mN·m (306gf·cm).
AB
Figure 4-7.
Master plane Reel disk height
adjusting jig
Mechanism chassis
Reel disk
10 ±0.2mm Reel disk
CHECKING AND ADJUSTMENT OF TAKE-UP
TORQUE IN FAST FORWARD MODE
• Remove the cassette housing control assembly.
• After short-circuiting TP801 provided at the center
(facing to the main PWB), plug in the power cord.
• Setting
1. Set a torque gauge to zero on the scale. Place it on the
take-up reel disk.
2. Press the FF button.
3. To calculate the remaining capacity of the play back
mode, slowly rotate the supply reel disk, and then shift
it into the forward mode.
• Checking
1. Turn the torque gauge slowly (one rotation every 2 to 3
seconds) by hand in the CW direction.
2. Makesurethatthe indication of torque gaugeisnotless
than 30mN·m (306gf·cm).
Figure 4-9.
Torque gauge
30mN·m (306gf·cm)
or more
Supply reel disk
Idler ass'y
The gauge is held at
its maximum value.
(Red mark)
• Adjustment
1. Iftherewindwinding-uptorqueislessthanthespecified
value, clean the capstan D.D. motor pulley, drive belt,
andlimiterpulleywith cleaning liquid, rewind again,and
check the winding-up torque.
2. If the winding-up torque is still out of range, replace the
drive belt.
Figure 4-8.
Torque gauge
30mN·m (306gf·cm)
or more
The gauge is held at
its maximum value.
(Red mark)
Idler ass'y
• Adjustment
1. If the FF winding-up torque is less than the specified
value,cleanthecapstanD.D.motorpulley,reelbelt,and
limiter pulley with cleaning liquid, and check again.
2. If the torque is less than the set value, replace the reel
belt.
CCW
CW

14
VC-S2000HM
Notes:
1. Hold the torque gauge by hand so that it is not moved.
2. Donotkeepthereeldiskinlockstate.Donotallowlong-
time measurement.
CHECKING AND ADJUSTMENT OF TAKE-UP
TORQUE IN RECORD/PLAYBACK MODE
• Remove the cassette housing control assembly.
• After short-circuiting TP801 provided at the center
(facing to the main PWB), plug in the power cord.
• Turn off the power switch.
• Open the cassette torque meter lid, and fix it with
tape.
• Load the cassette torque meter into the unit.
• Put the weight (500g) on the cassette torque meter.
• Turn on the power switch.
• Press the REC button, and set LP picture record
mode.
CHECKING AND ADJUSTMENT OF TAKE-UP
TORQUE IN VIDEO SEARCH REWIND MODE
• Remove the cassette housing control assembly.
• After short-circuiting TP801 provided at the center
(facing to the main PWB), plug in the power cord.
• Setting
Press the playback button and rewind button to set the
video search rewinding mode.
• Checking
Place the torque gauge on the supply reel disk, and turn it
counterclockwise very slowly (one rotation every 1 to 2
seconds) and check that the torque is within the set value
14.0 ±3.9mN⋅m. (144 ±40gf⋅cm)
Figure 4-11.
Torque gauge
Supply reel disk
Note:
Surely put the torque gauge on the reel disk to measure. If
the torque gauge is raised, accurate measurement is
impossible.
• Adjustment
Iftherewindingplaybackwinding-uptorqueisnotwithinthe
setting, replace the limiter pulley assembly.
Note:
The winding-up torque fluctuates due to variation of rota-
tion torque of supply reel disk. Read the center value of
fluctuation as setting.
CCW
Set value LP6.9 ±2.5mN⋅m (70 ±25gf⋅cm)
500g
Cassette torque meter
Figure 4-10.
• Checking
1. Make sure that value is within the setting 6.9±2.5mN·m
(70±25gf·cm).
2. The winding-up torque fluctuates due to variation of
rotation torque of limiter pulley ass'y. Read the center
value of fluctuation as setting.
3. SettheLPrecordmodeandmakesurethatthewinding-
up torque is within setting.
• Adjustment
If the playback winding-up torque is not within the setting,
replace the limiter pulley assembly.
Note:
When the torque cassette is set, put a weight (500g) to
prevent rise.
When the cassette torque meter is taken out.
Turn off the power switch.

15
VC-S2000HM
Figure 4-13.
1. Detach the pinch roller from the capstan shaft.
Do not separate excessively. Or the pinch lever and
pinch double action lever may disengage.
2. Engage the tension gauge adapter with the pinch roller
shaft, and pull in the arrow direction.
3. Gradually return the pinch roller, and measure the
pulling force when the pinch roller contacts the capstan
shaft.
4. Make sure that the measured value is within setting 8.8
to 11.8 N (900 to 1,200gf).
CHECKING AND ADJUSTMENT OF TENSION
POLE POSITION
• Remove the cassette housing control assembly.
• After short-circuiting TP801 provided at the center
(facing to the main PWB), plug in the power cord.
• Setting
1. Turn off the power switch.
2. Open the cassette tape (E-180), and fix with tape.
3. Set the cassette tape in loading state.
4. Put the weight (500g) on the cassette tape.
5. Turn on the power switch.
6. MaketheadjustmentwiththebeginningofaE-180tape.
CHECKING THE VIDEO SEARCH REWIND
BACK TENSION
• Remove the cassette housing control assembly.
• After short-circuiting TP801 provided at the center
(facing to the main PWB), plug in the power cord.
• Checking
1. After pressing the play button, press the rewind button,
and set the video search rewind mode.
2. Placethetorquegaugeonthetake-upreeldisk,andturn
it counterclockwise very slowly (one rotation every 2 to
3 seconds) and check that the torque is within the set
value 3.4±1.5mN⋅m (35±15gf⋅cm).
Pinch roller Tension gauge
8.8 ~ 11.8 N
(900 - 1,200gf)
Capstan shaft
Tension gauge adapter
Figure 4-12.
Torque gauge
Take-up reel disk
Notes:
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
• Remove the cassette housing control assembly.
• After short-circuiting TP801 provided at the center
(facing to the main PWB), plug in the power cord.
• Checking
Press the play button to set the playback mode.
CCW
Figure 4-14.
500g
(E-180)
Weight to prevent
float (500g)
• Checking
1. Set a cassette tape, push the REC button to place the
unit in the SP record mode. Now check the tension pole
position.

16
VC-S2000HM
2. Visuallycheck toseeiftherightedgeofthe tensionpole
is within the 2.3 ±0.25 from the right edge of the Sup
guide shaft.
Insert the slotted screwdriver in the tension pole adjuster,
and rotate clockwise.
Figure 4-17.
At left side from the center line
Figure 4-15.
Figure 4-16.
Insert the slotted screwdriver in the tension pole adjuster,
and rotate counterclockwise.
At right side from the center line
Tension pole adjuster adjusting range
2.3 ±0.25
2.3 ±0.25
2.3 ±0.25
Sup guide shaft
Adjust so that the delta mark of tension pole adjuster is
within 90°range (left, right).
CHECKING AND ADJUSTMENT OF RECORD/
PLAYBACK BACK TENSION
• Remove the cassette housing control assembly.
• After short-circuiting TP801 provided at the center
(facing to the main PWB), plug in the power cord.
• Setting
1. Turn off the power switch.
2. Open the torque cassette meter and fix with tape.
3. Set the cassette tape in loading state.
4. Put the weight (500g) on the cassette torque meter.
5. Turn on the power switch.
Make the adjustment with the beginning of a E-180 tape.
Tension pole adjuster
90°
90°
Figure 4-18.
Tension pole
500g
Weight to prevent
float (500g)
Cassette torque
meter
Figure 4-19.
• Checking
1. Push the REC button to place the unit in the SP record
mode.
2. At this time ascertain that the back tension is within the
setting (36.5 to 52g·cm) by seeing the indication of
torque cassette meter.

17
VC-S2000HM
• Remove the cassette housing control assembly.
• After short-circuiting TP801 provided at the center
(facing to the main PWB), plug in the power cord.
• Setting
1. Set a torque gauge to zero on the scale. Place it on the
supply reel disk.
2. Switch from the FF mode to the STOP mode.
3. Disconnect the power cord.
• Checking
Turn the torque gauge at a rate of about one turn/2 sec
in the CW direction/CCW direction with respect to the
supply reel disk so that the reel disk and torque gauge
pointer rotate at equal speed, and make sure that the
valueiswithinthesetting(CWdirection:4.9to13.7mN·m
(50 to 140gf·cm); CCW direction: 2.9 to 9.8mN·m (30 to
100gf·cm).
• Adjustment
1. If the indication of torque cassette meter is lower than
the setting, shift the tension spring engagement to the
part A.
2. If the indication of torque cassette meter is higher than
the setting, shift the tension spring engagement to the
part B.
• Checking the brake torque at the take-up side
Figure 4-22.
CCW: 4.9~13.7mN⋅m (50~140gf⋅cm)
CW: 3.9~10.8mN⋅m (40~110gf⋅cm)
Figure 4-20.
CHECKING THE BRAKE TORQUE
• Checking the brake torque at the supply side
CCW: 2.9~9.8mN⋅m (30~100gf⋅cm)
CW: 4.9~13.7mN⋅m (50~140gf⋅cm)
Figure 4-21.
Tension arm
Tension spring
CW
CCW CW
Supply reel disk
Torque gauge
Torque gauge
CCW
Take-up reel
disk
AB
• Remove the cassette housing control assembly.
• After short-circuiting TP801 provided at the center
(facing to the main PWB), plug in the power cord.
• Setting
1. Switch from the FF mode to the STOP mode.
2. Disconnect the power cord.
3. Set a torque gauge to zero on the scale. Place it on the
take-up reel disk.
• Checking
1. Turn the torque gauge at a rate of about one turn/2 sec
in the CCW direction/CW direction so that the reel disk
and torque gauge pointer rotates at equal speed and
make sure that the value is within the setting (CCW
direction: 4.9 to 13.7mN·m (50 to 140gf·cm), CW direc-
tion: 3.9 to 10.8 mN·m (40 to 110gf·cm).
2. Adjustmentofthebraketorqueatthesupplysideandthe
take-up side
• Unless the supply side brake torque or take-up side
brake torque is within the setting, clean the felt surface
of reel disk (supply, take-up) brake lever, check again
the brake torque.
• If value cannot be set within the setting yet, replace the
main brake ass'y or main brake spring.

18
VC-S2000HM
Figure 4-24.
• Replacement
1. Solder the removed PWB to the new head assembly.
2. AdjusttheheightfromtheA/Cheadplate(lowersurface)
to the A/C head base to 10.8mm with slide calipers. (3
places of azimuth screw section, tilt screw section and
hight screw section) (See the figure below.)
3. Align the left end of gear of A/C head plate with the
punched mark of chassis, tentatively tighten the screws
1and 2so as to ensure smooth motion of A/C head
plate. Tentative tightening torque must be 0.15 to 0.20
N·m (1.5 to 2.0kgf·cm).
REPLACEMENT OF A/C (Audio/Control) HEAD
1. Remove the cassette housing control assembly.
2. In unloading state unplug the power cord.
• Removal
1. Removethescrews123,Azimuthscrew,Tiltscrew.
2. Unsolder the PWB fitted to the A/C head.
Notes:
1. When replacing, never touch the head. If you touched,
clean with the cleaning liquid.
2. When removing the screw 3, take care so that the
spring may out.
New A/C head ass'y
A/C head PWB
2
Spring 1
Solder
❈Never touch the head
10.8mm10.8mm
Azimuth screw
Height screw
Tilt screw
A/C head base
Figure 4-25.
Note:
1. Ifthescrews1and2aretightententativelytooloose,
the azimuth and height of A/C head may change when
theyarefinallytightened.Thereforecaremustbetaken.
2. After completion of A/C head be sure to adjust tape
running.(Executetherunningadjustmentbythemethod
described in Page 20, 21.)
Punched line mark on chassis
Left end of A/C head plate gear
1
2
3
Height screw
Figure 4-23.
3

19
VC-S2000HM
500g
Figure 4-26.
Figure 4-27.
Height screw
Azimuth screw
Tilt screw
Cassette tape
Mechanism chassis
Tape
0.3mm
A/C head
• Adjustment
Adjust the height screw visually so that the control head is
visible 0.3mm below the bottom of the tape.
1. Set the cassette tape in the unit.
2. Press the PLAY button to put the unit in the playback
mode.
3. Roughlyadjustthe heightoftheA/C headbyturningthe
height screw until the tape is in the position shown
below.
A/C HEAD HEIGHT ROUGH ADJUSTMENT
• Setting
HEIGHT ADJUSTMENT OF REVERSE GUIDE
1. Adjust the height from the mechanism chassis to the
reverse guide lower flange to 13.38 mm, using the
reverse guide height adjustment jig, in tape loading
state. (Refer to Figure 4-28 (a) (b).)
Figure 4-29.
3. Setthetape,andcheckfortapecreasenearthereverse
guide in the playback mode.
Ifcreaseis found, turnthereverseguideadjustment nut
toremovecrease.(AsforcreasecheckrefertoFigure4-
30.)
(a) (b)
Figure 4-28.
2. Rotate counterclockwise the reverse guide height ad-
justment nut 1/10 turn. (For height adjustment use the
reverseguideheightadjustmentboxdriver(JiGDRiVER
11055)).
13.38mm
Box driver
Height adjusting nut
500g
Capstan
motor shaft
Mechanism
chassis
Reverse guide An example of
crease near the
reverse guide
Weight to
prevent float (500g)
Fixing guide
* Check for crease from the A direction.
Figure 4-30.
CCW
A
Reverse guide height
adjusting jig
Reverse guide height
adjusting jig
Reverse guide
Mechanism
chassis
Weight to prevent
float (500g)

20
VC-S2000HM
ADJUSTMENT OF TAPE DRIVE TRAIN
1. Tape run rough adjustment
1Remove the cassette housing control assembly.
2After shortcircuiting TP801 provided at the center
(facing to the main PWB), plug in the power cord.
3Check and adjust the position of the tension pole.
(See page 15.)
4Check and adjust the video search rewind back
tension. (See page 15.)
5Connect the oscilloscope to the test point for PB
CHROMA envelope output (TP201). Set the syn-
chronism of the oscilloscope to EXT. The PB
CHROMA signal is to be triggered by the head
switching pulse (TP202).
6Set the alignment tape (VROCPSV) to play. (Put a
500g weight on the cassette tape to prevent lift of
cassette tape.)
Notes:
1. Previouslysetthetrackingcontrolinthecenterposition,
and adjust the envelop waveform to maximum with X
value adjustment nut. Thereby the tape run rough ad-
justment is facilitated.
2. Especiallytheoutletsideenvelopewaveformmusthave
higher flatness.
500g
Figure 4-31.
7Press the tracking button (+), (–) and change the
envelopewaveformfrommaxtominandfromminto
max. At this time make sure that the envelope
waveform changes nearly parallel.
8Unless the envelope waveform changes nearly par-
allel, adjust the height of supply side and take-up
side guide roller so that the envelope waveform
changes nearly parallel. (For envelop adjustment
procedure refer to Figure 4-35.)
9Turn the tilt screw to remove the tape crease at the
fixing guide flange.
Playback the tape and check for tape crease at the
fixing guide flange.
(1)If there is no tape crease
Turn the tilt screw clockwise so that tape crease
appearsonceattheflange,andthenreturnthetilt
screw so that the crease disappears.
(2)If there is tape crease
Turn counterclockwise the tilt screw so that the
tape crease disappears.
(Reference) If the tilt screw is turned clockwise
crease appears at the lower flange.
Guide roller
Weight of 500g
Cassette Tape
2. Adjustment of A/C head height and azimuth
1PerformtheinitialsettingofA/Cheadpositionbythe
method stated in "Page 18 Replacement 3".
2Connect the oscilloscope to the audio output termi-
nal.
3Usingthe alignmenttapeinwhich1kHzlinearaudio
signalhasbeenrecorded,adjusttheheightscrewso
as to get max audio output.
4Usingthe alignmenttapeinwhich6kHzlinearaudio
signal has been recorded, adjust the azimuth screw
so as to get max audio output.
5Repeat the above adjustment steps 3and 4a
couple of times. Finally take the step 4 again.
Figure 4-32.
For X value adjustment
Adjust the X value, turning the gear-
type screwdriver.
Figure 4-33.
3. Tape run adjustment
1ConnecttheoscilloscopetoPBCHROMAenvelope
output test point, set oscilloscope sync to EXT,
trigger-input the PB CHROMA signal (head switch-
ing pulse).
2Rough adjustment of X value
Tentativelyfix A/Cheadarmscrews1and2by the
method described in Page 18 "Replacement 3".
Playback the alignment tape (VROCPSV) and
shortcircuit TP802. As a result the auto-tracking is
automatically cancelled, so that the X value adjust-
ment mode is set.
MovetheA/CheadwiththeXvalueadjustmentgear
driver (JiGDRiVER-6) by the method shown in Fig-
ure 4-33, and adjust the A/C head so as to get the
maximum envelope waveform. (Note: When the A/
C head is adjusted, adjust so that the maximum
envelop waveform is obtained nearest the position
of initial setting made in Page 18.)