Sharp VC-G20SM User manual

VC-G20SM/G200SM
VC-G201SM/G401SM
SHARP CORPORATION
SERVICE MANUAL
SERVICE-ANLEITUNG
VIDEO -CASSETTEN RECORDER
VIDEO CASSETTE RECORDER
Page
1. SPECIFICATIONS.......................................... 3
2. DISASSEMBLY AND REASSEMBLY ............ 4
3. FUNCTION OF MAJOR MECHANICAL
PARTS ............................................................ 6
4. ADJUSTMENT, REPLACEMENT
AND ASSEMBLY OF MECHANICAL
UNITS ............................................................. 8
5. ELECTRICAL ADJUSTMENT ........................ 27
6. MECHANISM OPERATION FLOW CHART
AND TROUBLESHOOTING GUIDE .............. 33
7. TROUBLESHOOTING.................................... 39
8. BLOCKDIAGRAMS ........................................102
9. SCHEMATIC DIAGRAM AND PWB FOIL
PATTERN .......................................................112
10. REPLACEMENT PARTS LIST .......................129
11. EXPLODED VIEWS........................................137
12. PACKING OF THE SET .................................142
CONTENTS
Seite
1. TECHNISCHE DATEN ................................... 3
2. AUSBAU UND
WIEDERZUSAMMENBAU.............................. 53
3. FUNKTIONEN DER WICHTIGSTEN
MECHANISCHEN TEILE................................ 55
4. EINSTELLUNG, AUSTAUSCH UND
MONTAGE DER MECHANISCHEN ............... 57
5. ELEKTRISCHE EINSTELLUNG ..................... 76
6. ABLAUFDIAGRAMM ZUR LAUFWERKS-
FUNKTION UND FEHLERSUCHTABLLE ...... 82
7. FEHLERSUCHE ............................................. 88
8. BLOCKSCHALTBILD......................................102
9. SCHALTSCHEMA UND
PLATINENMUSTER .......................................112
10. ERSATZTEILLISTE ........................................129
11. EXPLOSIONSDARSTELLUNGEN .................137
12. VERPACKUNG DES GERÄTES ....................142
INHALT
ImInteresse derBenutzer-Sicherheit(gemäßden Sicherheitsvorschriften
in eingen Ländern) sollte dieses Gerät wieder auf seinen ursprünglichen
ZustandeingestelltundnurdievorgeschriebenenTeileverwendetwerden.
In the interests of user-safety (Required by safety regulations in some
countries) the set should be restored to its original condition and only parts
identical to those specified should be used.
MODELS
MODELLE
VC-G20SM
VC-G200SM
VC-G201SM
VC-G401SM
VC-G20SM
VC-G200SM/G201SM/G401SM
S82N8VC-G20SM

2
VC-G20SM/G200SM
VC-G201SM/G401SM
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.
When checking the soldering side in the tape travel
mode,makesurefirstthatthetapehasbeenloadedand
then turn over the PWB with due care to the primary
power circuit.
Makereadjustment, 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 : S704
Adjustthenotchoftheparttothewhitemarkerofthe
symbol on the PWB. Do not allow any looseness.
(4) Take-up and supply sensors : D706 and
D707
Be careful not to confuse the setting direction of the
partsinreferencetothesymbolsonthePWB.Donot
allow any looseness.
VORSICHTSMASSNAHMEN BEIM
AUSWECHSELN VON TEILEN
Bei Wartungsarbeiten am Gerät mit eingeschalteter
Stromversorgung ist besonders auf den weiß
markierten Abschnitt zu achten.
Es handelt sich um den Primärstromkreis, der
spannungsführend ist.
Beim Überprüfen der Lötseite im Bandlaufmodus muß
zunächstsichergestelltwerden,daßdasBandeingezogen
wurde.DanndiePlatineunterentsprechenderBeachtung
des Primärstromkreises umdrehen.
Eine ggf. erforderliche Neueinstellung nach dem
Auswechseln von Teilen druchführen während sich
Bandlaufwerk und Platine im Hauptrahmen befinden.
(1) Start- und Endsensoren: Q701 und Q702
Das hervorstehende Teil des Sensors tief in die
obereÖffnung desHalterstecken. Die Sensoren in
Bezug auf die Platine ausreichend befestigen.
(2) Fotokoppler: IC901 und IC902
Siehe das Symbol auf der Platine und die
Anodenkennzeichnung des Teils.
(3) Nockenschalter A und B: S704
Die Kerbe des Teils mit der weißen Markierung des
SymbolsaufderPlatineausrichten. DieTeilemüssen
fest sitzen.
(4) Aufwickel-undAbwickelsensoren:D706
und D707
Darauf achten, daß die Ausrichtung der Teile in
Bezug auf die Symbole auf der Platine nicht
vertauscht wird.

3
VC-G20SM/G200SM
VC-G201SM/G401SM
1. SPECIFICATIONS
Format: VHS PAL standard
Video recording system: Two rotary heads, helical scan system
Video signal: PAL/MESECAMcolourandB/Gsignals,
625 lines
Recording/playing time: 240 min max. with SHARP E-240 tape
(PAL SP)
480 min max. with SHARP E-240 Tape
(PAL LP) (VC-G401SM)
Tape width: 12.7mm
Tape speed: 23.39 mm/s (PAL SP)
11.70 mm/s (PAL LP) (VC-G401SM)
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: AC230V, 50Hz
Power consumption:
Approx. 11W
3W max. (at Standby mode)
Operating temperature: 5°C to 40°C
Storage temperature: –20°C to 55°C
Weight: Approx. 2.5 kg
Dimensions: 360mm(W)x231.4mm(D)x92.5mm(H)
(VC-G200SM/G201SM/G401SM)
360mm(W)x229.0mm(D)x92.0mm(H)
(VC-G20SM)
VIDEO
Input: 1.0 Vp-p, 75 ohm
Output: 1.0 Vp-p, 75 ohm
Horizontal resolution: 250 lines
AUDIO 0 dBs = 0.775 Vrms
Input: Line1; –3.8 dBs, 10k ohm
Line2; –3.8dBs, 10k ohm
(VC-G20SM/G201SM/G401SM)
Output: Line1; –3.8 dBs, 1k ohm
Line2; –3.8dBs, 1k ohm
(VC-G20SM/G201SM/G401SM)
Accessories included: 75 ohm coaxial cable
Operation manual
Infrared remote control
Battery (2pcs.)
Note:
The antenna must correspond to the new standard DIN 45325
(IEC 169 - 2) for combined UHF/VHF antenna with 75 ohm connector.
1. TECHNISCHE DATEN
Format: VHS PAL Norm
Video-Aufzeichnungssystem: Schrägspuraufzeichnung mit zwei
rotierenden Köpfen
Videosignale: PAL/MESECAM-Farb-und
B/G-weißsignale, 625 Zeilen
Aufzeichnungs-/: 240 Minuten Max., mit SHARP E-240-
Band (PAL-SP)
480 Minuten Max., mit SHARP E-240-Band
(PAL-LP) (VC-G401SM)
Wiedergabezeit
Bandbreite: 12,7 mm
Bandgeschwinddigkeit: 23,39 mm/s (PAL-SP)
11,70 mm/s (PAL-LP) (VC-G401SM)
Antenne: 75 Ohm unsymmetrisch
Empfangskanäle: VHF-Kanäle E2-E12, S1-S41
UHF-Kanäle E21-E69
Ausgangssignal HF-Wandler: UHF-Kanäle E21-E69
(voreingestellt auf Kanäl E36)
Stromversorgang: Wechselstrom 230V, 50Hz
Leistungsaufnahme: Ca. 11W
3 W max. (im Schlummermodus)
Betriebstemperatur: 5° bis 40°C
Legerungs temperatur: –20° bis 55°C
Gewicht: Ca. 2,5 kg
Abmessungen: 360mm(B)x231.4mm(T)x92.5mm(H)
(VC-G200SM/G201SM/G401SM)
360mm(B)x229.0mm(T)x92.0mm(H)
(VC-G20SM)
VIDEO
Eingang: 1,0 Vs-s, 75 Ohm
Ausgang: 1,0 Vs-s, 75 Ohm
Horizontale Auflösung: 250 Linie
AUDIO 0 dB = 0,775 Veff
Eingang: Direkteingang 1 : –3,8 dBs/10k Ohm
Direkteingang2 : –3.8 dBs/10k Ohm
(VC-G20SM/G201SM/G401SM)
Ausgang: Direktausgang 1 : –3,8 dBs/1k Ohm
Direktausgang 2 : –3.8 dBs/1k Ohm
(VC-G20SM/G201SM/G401SM)
Mitgeliefertes Zubehör: 75 Ohm-Koaxialkabel
Bedienungsanleitung
Infrarot-Fernbedienung
Batterie (2 Stücks)
Hinweis:
Die Antenne muß der neuen DIN-Norm 45325 (IEC169-2) für VHF-
UHF-Kombiantennen mit 75 Ohm-Anschluß entsprechen.
As part of our policy of continuous improvement, we reserve the
right to alter design and specifications without notice. *
Im Sinne der ständigen Verbesserung behalten wir uns das Recht vor, die
äußereAufmachungundtechnischenDaten ohne Vorankündigung zu ändern.

4
VC-G20SM/G200SM
VC-G201SM/G401SM
8
A
D
7
7
9
1
C
242
4
5
B
E
B
D
A
C
6
D
VC-G20SM
FRONT PANEL
B
3
3
VC-G200SM/G201SM/G401SM
FRONT PANEL
B
3
3
6
E
TOP CABINET
TOP CABINET
FIX ANGLE
MAIN FRAME
OPERATION PWB
ANTENNA
TERMINAL
COVER
EUR-TERM PWB
MAIN PWB
MECHANISM
CHASSIS
CASSETTE
HOUSING
CONTROL
F
F
7
7
ANTENNA
TERMINAL
COVER
EUR-TERM PWB
(VC-G200SM)
(VC-G20SM,
G201SM,G401SM)
2. DISASSEMBLY AND REASSEMBLY
2-1 DISASSEMBLY OF MAJOR BLOCKS
TOP CABINET : Remove 2 screws 1.
FRONT PANEL : Remove 2 screws 2and 7 clips 3.
MECHANISM/ : Remove 2 screw 4, 1 screw 5.
MAIN PWB Remove2screws6and2screws7
with antenna terminal cover. Remove
1screw 9. Remove 1 screw 8 with
top cabinet fix angle.

5
VC-G20SM/G200SM
VC-G201SM/G401SM
Pinch Drive Cam
Synchro Gear Master cam
Main Chassis
Drive Lever
2-2 CARES WHEN REASSEMBLING
INSTALLING THE CASSETTE HOUSING
When the cassette housing is installed on the mechanism,
the initial setting is essential condition.
Therearetwoinitialsettingmethods,namelyelectricaland
mechanical.
1. Electrical initial setting
So as to perform initial setting of mechanism execute the
Step1ofInstallationofcassettehousing.Afterascertaining
the return to the initial setting position install the cassette
housing. (Conditions: When mechanism and PWB have
been installed)
2. Mechanical initial setting
• Rotatethewormgearbypushingtheflangemanuallyuntil
return to initial position.
• When apply power supply to rotate the loading motor,
please remove/unsolder at least one terminal wire.
• If voltage applied to loading motor without diconnecting
the terminal wire, there is a possibility the capstan motor
IC will damage.
• The maximum applied voltage is 9V. If more than 9V,
there is apossibility the mechanism will damage.
• After ascertaining the return to the initial set position
installthecassettehousinginthespecifiedposition.(This
method is applied only for the mechanism.)
AH CONNECTOR
AE CONNECTOR
END SENSOR
END TIP SW
AA CONNECTOR
AD CONNECTOR
MODE SW
START SENSOR
90¡
180¡
270¡
0¡
MASTER CAM POSITION
This positioning hole
should be at front side.
INSTALLING THE MECHANISM ON PWB
Lower vertically the mechanism, paying attention to the
mechanism edge mode SW position, (Set the mode SW
position to 270° and make sure the master cam position
hole also in 270° position) and install the mechanism with
due care so that the parts are not damaged.
* Please make sure to insert correctly.
If not, strange moving will occur and will couse mecha-
nism damage.
PARTS WHICH NEED PARTICULAR CARE
When installing the mechanism chassis on the PWB unit,
take care so as to prevent deformation due to contact of
mechanism chassis with REC TIP SW.

6
VC-G20SM/G200SM
VC-G201SM/G401SM
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
4 Idler wheel ass’y
5 Open guide
6 Supply reel disk
7 Supply main brake
8 Take-up main brake
9 Pinch drive cam
10 A/C head ass’y
11 Reverse guide lever ass’y
12 Reel relay gear
13 Take-up reel disk
14 Pinch roller lever ass’y
15 Drum ass'y
16 Loading motor block
17 Drum driver motor
18 Take-up pole base ass'y
26 Auto head cleaner Ass'y
(VC-G401SM ONLY)
17 15 26
11
5
9
14
12
8
16
13
4
6
2
7
3
1
18 10

7
VC-G20SM/G200SM
VC-G201SM/G401SM
FUNCTION OF MAJOR MECHANICAL PARTS (BOTTOM VIEW)
No. Function No. Function
19 Syncro Gear
20 Master cam
21 Capstan D.D. motor
22 Reel belt
23 Clutch lever
24 Limiter pulley ass’y
25 Shifter
25
24
21
22
19
20
23

8
VC-G20SM/G200SM
VC-G201SM/G401SM
VROUBZFS CK
11. JiGHMEC-M005
10. JiGDRiVER-6 BM
9. JiGDRiVERH-4 AP
4. Torque Driver JiGTD1200 CB
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
JiGRH0002 BR
JiGSG2000 BS
JiGSG0300 BF
7. JiGADP003 BK
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
2.0 kg.
Thesetapes are especially used for
electrical fine adjustment.
Video Audio HiFi Audio Track
625 Monoscope 6kHz — 49µm
PAL Colour Bar 1kHz — 49µm
This screwdriver is used for adjusting the
guide roller height.
For X value adjustment
This Jig is used for adjustment
of tension pole.
X value adjustment
gear driver
Tension Pole
Adjustment Driver
2. Torque Gauge
6.
5.
8. Alignment Tape
Guide roller height
adjustment driver

9
VC-G20SM/G200SM
VC-G201SM/G401SM
4-2 MAINTENANCE CHECK ITEMS AND EXECUTION TIME
Perform the maintenance with the regular intervals as follows so as to maintain the quality of machine.
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
Colour and beating
Small sound or sound
distortion
Poor S/N ratio, no colour
Poor flatness of the
envelope with alignment
tape
No tape running,
uneven colour
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.
Screen swaying
Cassette not loaded or
unloaded
No tape running, tape
slack
Tape slack
Video head cleaning procedure
1. Apply one drop of cleaning liquid to the cleaning paper with the baby oiler.
2. Gentlypressthecleaningpaperagainstthevideoheadtofixyourfinger,andmovetheupperdrumsothateachhead
is passed to and fro 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
Gently press the cleaning paper to
fix with your finger, and rotate the
upper drum to clean.
Move to and fro 5 times for each head.
(Do not move the cleaning paper.)
Rotate the upper drum
with one hand.

10
VC-G20SM/G200SM
VC-G201SM/G401SM
Figure 4-1.
• Reassembly
1. Before installing the cassette housing control, short-
circuit between TP803 and TP802 provided at main
PWB, press the eject button. The master cam turns and
stop in eject position. Fit the drive lever to master cam
through main chassis, push down and slide the drive
lever towards to master cam.
*Ejectposition:PinchDrive Campositioning holeparal-
lel to center of Synchro Gear (Synchro gear marking
line). Synchro Gear positioning mark parallel to center
of master cam.
Figure 4-2.
2. Install in the reverse order of removal.
Notes
1. Inthecasewhenyouusethemagnetscrewdriver,never
approach the magnet driver to the A/C head, FE head,
and drum.
2. When installing or removing, take care so that the
cassette housing control and tool do not contact the
guide pin or drum.
3. After installing the cassette housing control once per-
form cassette loading operation.
4-4 TORUNATAPEWITHOUTTHECASSETTE
HOUSING CONTROL ASSEMBLY
1. Remove the full-surface panel.
2. Short-circuit between TP803 and TP802.
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.
4-3 REMOVING AND INSTALLING THE CAS-
SETTE 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) Pullandcirclethedriveleverandpull up the cassette
housing control.
Figure 4-3.
9. Turn on the power switch.
10. Perform running test.
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.
1
500g
Weight to prevent
float (500g)
Mechanism chassis
From Bottom View
Pinch Drive
Cam
Synchro
Gear
Master
cam
From top view
Main chassis
Drive
Lever
Phase
matching
Master cam
Line of
synchro
gear.
Hole of Pinch
drive cam.