Sharp VC-A10, VC-A10S, VC-A50, VC-A50S, VC-A500 Service manual

...

VC-A500

VC-A10/A10S/A50/A50S/

A50S(B)/A60/A75/A80S

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

SERVICE MANUAL

S62L3VC-A10//

VIDEO CASSETTE PLAYER

VC-A10/A10S VC-A50/A50S/A50S(B) VC-A500 VC-A60 VC-A75

MODELS

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 be used.

CONTENTS

1. SPECIFICATIONS................................................................................................................. 2

2. DISASSEMBLY AND REASSEMBLY ................................................................................... 3

3. FUNCTION OF MAJOR MECHANICAL PARTS................................................................... 6

4. ADJUSTMENT, REPLACEMENT AND ASSEMBLY OF MECHANICAL UNITS .................. 9

5. ELECTRICAL ADJUSTMENT ............................................................................................. 28

6. MECHANISM OPERATION FLOWCHART AND TROUBLESHOOTING GUIDE............... 31

7. TROUBLESHOOTING ........................................................................................................ 37

8. BLOCK DIAGRAM............................................................................................................... 45

9. SCHEMATIC DIAGRAM AND PWB FOIL PATTERN ......................................................... 55

10. REPLACEMENT PARTS LIST ............................................................................................ 68

11. EXPLODED VIEW OF MECHANICAL PARTS ................................................................... 77

12. PACKING OF THE SET ...................................................................................................... 82

VC-A80S

Page

SHARP CORPORATION

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

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, make sure first that the tape has been loaded and then turn over 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: S704.

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: D707 and D706.

Be careful not to confuse the setting direction of the parts in reference to the symbols on the PWB. Do not allow any looseness.

1. SPECIFICATIONS

Format: VHS PAL/MESECAM/NTSC standard (except VC-A60)

VHS PAL/SECAM/MESECAM/NTSC standard (VC-A60)

Video recording system: Rotary, slant azimuth two heads helical scan system

Video signal: PAL colour or monochrome (CCiR system B/G) signals

Maximum Recording/playing time: 240 minutes max. with SHARP E-240 tape at SP mode)

480 minutes max. with SHARP T-160 tape (NTSC: EP mode)

Tape width: 12.7mm

Tape speed: 23.39/33.53 mm/s (PAL/NTSC : SP mode)

11.70/16.67 mm/s (PAL/NTSC: LP mode)

7.79/11.12 mm/s (PAL/NTSC: EP mode)

Antenna: 75 ohm unbalanced

RF converter output signal: UHF Channel E21-E69 (preset to E60)

Power requirement: AC110-240V, 50/60Hz

Power consumption: Approx. 10W (VC-A10/A10S,VC-A50/A50S/A50S(B)/A500/A60)

Approx. 12W (VC-A75) Approx. 13W (VC-A80S)

Operating temperature: 5°C to 40°C

Storage temperature: –20°C to 60°C

VIDEO Output: 1.0 Vp-p, 75 ohm AUDIO Output: Line -8 dBs/1k ohm

Weight: Approx. 2.3 kg

Dimensions: 360 mm (W) x 232 mm (D) x 92 mm (H)

Accessories included: 75 ohm coaxial cable

Operation manual Infrared remote control Battery Schematic Diagram (VC-A500)

As part of our policy of continuous improvement, we reserve the right to alter design and specifications without notice.

Note: The antenna must correspond to the new standard DIN 45325

(IEC 169 - 2) for combined UHF/VHF antenna with 75 ohm connector.

2. DISASSEMBLY AND REASSEMBLY

2-1 DISASSEMBLY OF MAJOR BLOCKS

TOP CABINET : Remove 2 screws 1. FRONT PANEL : Remove 2 screws 2 and 7 clips 3. MECHANISM/ : Remove 2 screw 4, 2 screws 5. MAIN PWB Remove 2 screws 6 with antenna

terminal cover. Remove 1 screw 7 with top cabinet fix angle.

TOP CABINET

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

VC-GH61GM/SM

FRONT PANEL

TOP CABINET FIX ANGLE

FRONT PANEL

OPERATION PWB

VC-GH611GM/SM

MAIN FRAME

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

2-2 DISASSEMBLING THE MECHANISM

1. When removing the mechanism from the set. Remove the screw 2 which connecting the PWB and the mechanism. Remove the screw 4 which connecting mechanism and main frame. Take out vertically the mechanism so that it does not damage the adjacent parts.

CASSETTE HOUSING

2. Removing the mechanism and cassette housing. Remove 2 screws 3 fixing the cassette housing to the mechanism, and remove the cassette housing.

MECHANISM CHASSIS

MAIN FRAME

2-3 CARES WHEN REASSEMBLING

Rotate the flange of worm gear by using thin stick. CW • • • Loading direction CCW • • • Ejection direction Note: Be careful not to damage the gear of worm gear and worm wheel gear. It miight cause a strange sound.

INSTALLING THE CASSETTE HOUSING

When the cassette housing is installed on the mechanism, 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 Step 1 of Installation of cassette housing. After ascertaining the return to the initial setting position install the cassette housing. (Conditions: When mechanism and PWB have been installed)

Pinch Drive Cam

Synchro Gear

Master cam

2. Mechanical initial setting

• Rotate the worm gear by pushing the flange manually until return to initial position.

Main Chassis

Drive Lever

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

• 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 install the cassette housing in the specified position. (This method is applied only for the mechanism.)

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.

END SENSOR

END TIP SW

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.

AE CONNECTOR

AH CONNECTOR

AA CONNECTOR

AD CONNECTOR

AC CORD

VC-A50 only

START SENSOR

90°

0°

This positioning hole should be at front side.

180°

270°

MODE SW

MASTER CAM POSITION

VC-A10/A10S/A500



VC-A50/A50S/A50SB VC-A60/A75/A80S

3. FUNCTION OF MAJOR MECHANICAL PARTS (TOP VIEW)



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



No. Function

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

8 Take-up main brake 9 Pinch drive cam

10 A/C head ass’y

18 Take-up pole base ass'

FUNCTION OF MAJOR MECHANICAL PARTS (BOTTOM VIEW)



(except VC-A50S)

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S



No. Function

19 Syncro Gear 20 Master cam 21 Capstan D.D. motor 22 Reel belt

No. Function

23 Clutch lever 24 Limiter pulley ass’y 25 Shifter

VC-A10/A10S/A500



VC-A50/A50S/A50SB VC-A60/A75/A80S

FUNCTION OF MAJOR MECHANICAL PARTS (BOTTOM VIEW)

(VC-A50S)



No. Function

19 Syncro Gear 20 Master cam 21 Capstan D.D. motor 22 Reel belt

No. Function

23 Clutch lever 24 Limiter pulley ass’y 25 Shifter 26 DM/LM FFC Holder

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

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.

No. Jig ltem Part No. Code Configuration Remarks

This cassette torque meter is used for check-

1. Torque Cassette Meter JiGVHT-063 CZ

JiGTG0090 CM

Torque Gauge

JiGTG1200 CN

3. Torque Gauge Head JiGTH0006 AW

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.

4. Torque Driver JiGTD1200 CB

Master Plane Jig and Reel Disk Height

5. Adjusting Jig

JiGRH0002 BR JiGMP0001 BY JiGSG2000 BS

Tension Gauge

JiGSG0300 BF

Pinch pressing force

7. JiGADP003 BK

measuring jig

Alignment Tape

Guide roller height

9. JiGDRiVERH-4 AP

adjustment driver

X value adjustment

10. JiGDRiVER-6 BM

gear driver Tension Pole

11. JiGHMEC-M005 Adjustment Driver

VROCPSV CK

When fixing any part to the threaded hole using resin with screw, use the jig. (Specified torque 5 kg)

These Jigs are used for checking and adjusting the reel disk height.

There are two gauges used for the tension measurements, 300 g and

2.0 kg. This Jig is used with the tension

gauge. Rotary transformer clearance adjusting jig.

These tapes are especially used for electrical fine adjustment.

Video Audio HiFi Audio Track 625 Monoscope 7k — 49µm PAL Colour Bar 1k — 49µm

This screwdriver is used for adjusting the guide roller height.

For X value adjustment

This Jig is used for adjustment of tension pole.

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

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.

Possible symptom

encountered

Abnormal rotation or significant vibration requires replacement.

Parts

Guide roller ass’y

Maintained

500 hrs.

1000 hrs.

1500 hrs.

2000 hrs.

Remarks

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

Lateral noises Head occasionally blocked

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

Screen swaying Cassette not loaded or

unloaded No tape running, tape

slack

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.

Supply/take-up main brake levers

Tape slack

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.

Video head cleaning procedure

1. Apply one drop of cleaning liquid to the cleaning paper with the baby oiler.

2. Gently press the cleaning paper against the video head to fix your finger, and move the upper drum so that each head 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.

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.

• Whenever the video head is cleaned, replace the cleaning 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

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) Pull and circle the drive lever and pull up the cassette

housing control.

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

2. Install in the reverse order of removal.

Notes

1. In the case when you use the magnet screw driver, 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 perform cassette loading operation.

4-4 TO RUN A TAPE WITHOUT THE CASSETTE

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.

Figure 4-1.

• Reassembly

1. Before installing the cassette housing control, shortcircuit 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.

*Eject position: Pinch Drive Cam positioning hole parallel to center of Synchro Gear (Synchro gear marking line). Synchro Gear positioning mark parallel to center of master cam.

Pinch Drive Cam

Synchro Gear

Master cam

Main chassis

Phase matching

Hole of Pinch drive cam.

Line of synchro gear.

Master cam

500g

Mechanism chassis

Weight to prevent float (500g)

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.

Drive Lever

From top view

From Bottom View

Figure 4-2.

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

4-5 REEL DISK REPLACEMENT AND HEIGHT

CHECK

• Removal

1. Remove the cassette housing control assembly.

2. Remove the Supply/Take-up main brake ass'y.

3. Remove tension band from the tension arm ass'y.

4. Remove the reel disk.

Note:

Take care so that the tension band ass'y and main brake ass'y are not deformed.

Tension arm ass'y

Ten

Tension band ass'y

Supply main brake

Take-up 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. Do not damage the Supply main brake ass'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 gear and to install a new take-up reel disk onto the shaft.

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. Take care so that grease does not adhere the brake surface.

2. After reassembly, check the video search rewind back tension (see 4-10), and check the brake torque (see 4-

14).

Take-up reel diskSupply reel disk

• Reassembly (Supply reel disk)

1. Clean the reel disk shaft and apply grease (SC-141) to it.

2. Match the phases of reel disk and reel relay gear, and set the new reel disk.

3. After checking the reel disk height, wind the tension band ass'y around the reel disk, and hook to tension arm ass'y.

4. Assemble the Supply main brake ass'y.

• 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 a little in the loading direction. Care must be taken since excessive shift results in damage.

Master plane

Supply reel disk

Cassette lock release shaft

Take-up reel disk

Figure 4-4.

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 disk height by changing the poly-slider washer under the reel disk.

Note:

Whenever replacing the reel disk, perform the height checking and adjustment.

Master plane

10 ± 0.2mm

Reel disk

Reel disk height adjusting jig

Mechanism chassis

Figure 4-5.

4-6 CHECKING AND ADJUSTMENT OF TAKE-

UP TORQUE IN FAST FORWARD MODE

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at 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.

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

Notes:

1. Hold the torque gauge by hand so that it is not moved.

2. Do not keep the reel disk in lock state. Do not allow longtime measurement.

4-7 CHECKING AND ADJUSTMENT OF TAKE-

UP TORQUE IN REWIND MODE

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at 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. Make sure that the indication of torque gauge is not less than 30mN·m (306gf·cm).

Torque gauge 3

• Checking

1. Turn the torque gauge slowly (one rotation every 2 to 3 seconds) by hand in the CW direction.

2. Make sure that the indication of torque gauge is not less than 30mN·m (306gf·cm).

Torque gauge

30mN·m (306gf·cm) or more

Idler ass'y

The gauge is held at its maximum value. (Red mark)

Figure 4-6.

• Adjustment

1. If the FF winding-up torque is less than the specified value, clean the capstan D.D. pulley, reel belt, and limiter pulley with cleaning liquid, and check again.

2. If the torque is less than the set value, replace the reel belt.

30mN·m (306gf·cm) or more

CCW

The gauge is held at its maximum value. (Red mark)

Supply reel disk

Idler ass'y

Figure 4-7.

• Adjustment

1. If the rewind winding-up torque is less than the specified value, clean the capstan D.D. pulley, reel belt, and limiter pulley with 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.

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

Notes:

1. Hold the torque gauge by hand so that it is not moved.

2. Do not keep the reel disk in lock state. Do not allow longtime measurement.

4-9 CHECKING AND ADJUSTMENT OF TAKE-

UP TORQUE IN VIDEO SEARCH REWIND MODE

• Remove the cassette housing control assembly.

4-8 CHECKING AND ADJUSTMENT OF TAKE-

UP TORQUE IN RECORD/PLAYBACK MODE

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at 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 picture record button, and set LP picture record mode (x2).

Set value LP 6.9

+2.0

mN⋅m (70

–2.5

500g

+20 –25

gf⋅cm)

• After short-circuiting between TP803 and TP802 provided at 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

14.1 ± 3.5mN⋅m. (144 ± 35gf⋅cm)

Torque gauge

CCW

Cassette torque meter

Figure 4-8.

• Checking

1. Make sure that value is within the setting 6.9 mN·m

+20

(70 gf·cm).

–25

+2.0 –2.5

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. Set the LP record mode (x2) and make sure that the winding-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.

Supply reel disk

Figure 4-9.

Note:

Surely put the torque gauge on the reel disk to measure. If the torque gauge is raised, accurate measurement is impossible.

• Adjustment

If the rewinding playback winding-up torque is not within the setting, replace the limiter pulley assembly.

Note:

The winding-up torque fluctuates due to variation of rotation torque of supply reel disk. Read the center value of fluctuation as setting.

4-10 CHECKING THE VIDEO SEARCH REWIND

500g

Weight to prevent float (500g)

(E-180)

BACK TENSION

• Remove the cassette housing control assembly.

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

• After short-circuiting between TP803 and TP802 provided at 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. 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 within the set value 3.7 ± 1.5mN⋅m (38 ± 15gf⋅cm).

Torque gauge

CCW

Take-up reel disk

Pinch roller

Capstan shaft

Tension gauge adapter

Tension gauge 900 - 1,200gf

Figure 4-11.

4-12 CHECKING AND ADJUSTMENT OF

TENSION POLE POSITION

∗∗

∗ Checking can be perform with or without

∗∗

cassette housing control.

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at main PWB, plug in the power cord.

Figure 4-10.

Notes:

Set the torque gauge securely on the take-up reel disk. If it is not secure, the measurement will be incorrect.

4-11 CHECKING THE PINCH ROLLER

PRESSURE

∗∗

∗ Checking can be perform with or without

∗∗

cassette housing control.

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at main PWB, plug in the power cord.

• Checking

Press the play button to set the playback mode.

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 change to 9.8 ± 2N (1.0 ± 0.2kgf).

• Setting (without cassette housing control)

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. Make the adjustment with the beginning of a E-180 tape.

• Setting (with cassette housing control)

1. Insert cassette tape (E-180).

2. Make the adjustment with the beginning of a E-180 tape.

Figure 4-12.

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

• 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.

2. Visually check to see if the position of the tension pole is within the 0 mm from the left side line.

+ 0.5 – 0.2

Standard A = 0 mm

+ 0.5

- 0.2

Tension pole adjustment driver adjusting direction

CCW

Tension pole adjustment driver

Figure 4-16.

Make the adjustment with the beginning of a E-180 tape.

Figure 4-13.

At left side from the reference line. (A).

Figure 4-14.

Insert the tension pole adjustment driver to main chassis hole, and rotate clockwise.

At right side from the reference line. (A).

4-13 CHECKING AND ADJUSTMENT OF

RECORD/PLAYBACK BACK TENSION

∗∗

∗ Checking can be perform with or without

∗∗

cassette housing control.

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at main PWB, plug in the power cord.

• Setting (without cassette housing control)

1. Turn off the power switch.

2. Open the cassette torque meter and fix with tape.

3. Set the cassette torque meter in loading state.

4. Put the weight (500g) on the cassette torque meter.

5. Turn on the power switch.

• Setting (with cassette housing control)

1. Insert cassette torque meter.

Figure 4-15.

Insert the tension pole adjustment driver to main chassis hole, and rotate counterclockwise.

500g

Cassette torque

Weight to prevent float (500g)

meter

Figure 4-17.

• 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 3.9 to 5.5mN⋅m (40 to 56gf·cm) by seeing the indication of torque cassette meter.

• 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.

Tension arm

Tension spring

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

• Checking the brake torque at the take-up side

Torque gauge

Take-up reel disk

CCW

Figure 4-18.

4-14 CHECKING THE BRAKE TORQUE

• Checking the brake torque at the supply side

Torque gauge

CCW

CCW: 4.41 ± mN⋅m (45 ± gf⋅cm) CW: 4.12 ± mN⋅m (42 ± gf⋅cm)

+2.0 –1.5 +1.5 –1.2

Figure 4-19.

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at main PWB, plug in the power cord.

Supply reel disk

+20 –15 +15 –12

CCW: 4.41 ± mN⋅m (45 ± gf⋅cm) CW: 4.12 ± mN⋅m (42 ± gf⋅cm)

+2.0 –1.5 +1.5 –1.2

+20 –15 +15 –12

Figure 4-20.

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at 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.

4. Please check Idler gear not contact with reel relay gear (TU side)

• 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: 4.41 ± 1mN·m (45 ± gf·cm), CW direction:

+1.5

4.12 ± 1.mN·m (42 to gf·cm).

–1.2

+2.0 –1.5

+15 –12

+20 –15

• 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.

4. Please check Idler gear not contact with reel relay gear (SU side)

• 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 value is within the setting (CW direction: 4.12 ± mN·m

+15

(42 gf·cm); CCW direction: 4.41 mN·m (45 15gf·cm).

–12

+2.0 –1.5

+1.5

–1.2 +20 –15

2. Adjustment of the brake torque at the supply side and the 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.

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

4-15 REPLACEMENT OF A/C (AUDIO/CONTROL)

HEAD

1. In eject position unplug the power cord.

• Removal

1. Take out FFC holder from main chassis. (Push 3 hooking point and pull-up the holder).

2. Remove the screws 123, Tilt screw.

3. 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.

A/C head screw

Azimuth spring

*Derection designation. (The bottom part is big.)

Azimuth adj. screw

A/C head PWB ass'y (with A/E)

Tilt screw

A/C head PWB

AC Head FFC Holder

3. Align the left end of gear of A/C head arm with the punched mark of chassis, tentatively tighten the screws 1 so as to ensure smooth motion of A/C head arm. Tightening torque must be 0.45 ± 0.05N·m (4.5 ±

0.5kgf·cm).

Height screw

Left end of A/C head arm gear Punched line mark on chassis

Figure 4-23.

Note:

1. If the screw 1 is tighten tentatively too loose, the azimuth and height of A/C head may change when they are finally tightened. Therefore care must be taken.

2. After completion of A/C head be sure to adjust tape running. (Execute the running adjustment by the method described in 4-17.)

Height adj. screw

A/C head plate

Height Adj. spring

Figure 4-21.

• Replacement

1. Solder the removed PWB to the new head assembly.

2. Adjust the height from the A/C head arm (lower surface) to the A/C head plate to 10.8mm with slide calipers. (3 places of azimuth screw section, tilt screw section and A/ C head front section) (See the figure below.)

New A/C head ass'y

A/C head PWB

Solder

A/C head plate

*Fit the groove of FFC to the boss of the holder.

A/C head FFC

A/C FFC holder

10.8mm

Figure 4-22.

4-16 A/C HEAD HEIGHT ROUGH ADJUSTMENT

• Setting

Azimuth screw

TiH screw

Height screw

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

4-17 ADJUSTMENT OF TAPE DRIVE TRAIN

1. Tape run rough adjustment 1 Check and adjust the position of the tension pole.

(See 4-12.)

2 Check and adjust the video search rewind back

tension. (See 4-10.)

3 Connect the oscilloscope to the test point for PB ATR

signal output (TP201). Set the synchronism of the oscilloscope to EXT. The PB ATR signal is to be triggered by the head switching pulse (TP202).

4 Set the alignment tape (VROCPSV) to play.

Guide roller

Cassette tape

500g

Mechanism chassis

Weight to prevent float (500g)

Figure 4-24.

1. Set the cassette tape in the unit.

2. Press the PLAY button to put the unit in the playback mode.

3. Roughly adjust the height of the A/C head by turning the height screw until the tape is in the position shown below.

A/C head

Tape

0.3mm

Figure 4-25.

• Adjustment

Adjust the height screw visually so that the control head is visible 0.3mm below the bottom of the tape.

Cassette Tape

Figure 4-26.

5 Press the tracking button (+), (–) and change the

ATR signal waveform from max to min and from min to max. At this time make sure that the ATR signal waveform changes nearly parallel.

6 Unless the ATR signal waveform changes nearly

parallel, adjust the height of supply side and take-up side guide roller so that the envelope waveform changes nearly parallel. (For ATR signal adjustment procedure refer to Figure 4-30.)

7 Turn 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 appears once at the flange, and then return the tilt 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.

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

Notes:

1. Previously set the tracking control in the center position, and adjust the ATR signal waveform to maximum with X value adjustment nut. Thereby the tape run rough adjustment is facilitated.

2. Especially the outlet side ATR signal waveform must have higher flatness.

Figure 4-27.

2. Adjustment of A/C head height and azimuth 1 Perform the initial setting of A/C head position by the

method stated in "4-15 Replacement 3".

2 Connect the oscilloscope to the audio output termi-

nal.

3 Using the alignment tape in which 1 kHz linear audio

signal has been recorded, adjust the height screw so as to get max audio output.

4 Using the alignment tape in which 7 kHz linear audio

signal has been recorded, adjust the azimuth screw so as to get max audio output.

5 The adjustment of 3 and 4 twice or three times

repeat, and finally adjust 4.

For X value adjustment Adjust the X value, turning the geartype screwdriver.

Figure 4-28.

3. Tape run adjustment 1 Connect the oscilloscope to PB ATR signal output

test point, set oscilloscope sync to EXT, trigger-input the PB CHROMA signal (head switching pulse).

2 Rough adjustment of X value

Tentatively fix A/C head arm screws 1 by the method described in 4-15 "Replacement 3". Playback the alignment tape (VROCPSV) and shortcircuit between TP801 and TP802. As a result the auto-tracking is automatically cancelled, so that the X value adjustment mode is set. Move the A/C head with the X value adjustment gear driver (JiGDRiVER-6) by the method shown in Figure 4-33, and adjust the A/C head so as to get the maximum ATR signal waveform. (Note: When the A/ C head is adjusted, adjust so that the maximum ATR signal waveform is obtained nearest the position of initial setting made in 4-15.)

3 Next, press the tracking button (+), (–) and change

the ATR signal waveform from max to min and from min to max. At this time adjust the height of supply and take-up side guide roller with the adjustment driver (JiGDRiVERH-4) so that the ATR signal waveform changes nearly parallel.

4 If the tape is lifted or sunk from the helical lead

surface, the PB ATR signal waveform appears as shown in Figure 4-30.

5 Press the tracking button (+), (–) and make sure that

the ATR signal waveform changes nearly parallel.

6 Finally, check tape crease near the reverse guide. If

tape crease is found, adjust tilt screw 45˚ counter clockwise. Small tape crcase will appear at retain guide after this adjustment finished.

Supply side

Take-up side Supply side Take-up side

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

PB ATR Signal

Head switching pulse

Figure 4-29.

4. A/C head X value adjustment 1 Fix A/C head arm screws 1 by the method described

in 4-15 "Replacement 3".

2 Playback the alignment tape (VROCPSV), and

shortcircuit between TP801 and TP802. As a result the auto-tracking is automatically cancelled, so that the X value adjustment mode is set.

When the tape is below the helical lead.When the tape is above the helical lead.

Adjustment

Supply side guide roller rotated in clockwise direction (lowers guide roller) to flatten ATR signal.

Take-up side guide roller rotated in clockwise direction (lowers guide roller) to flatten ATR signal.

Figure 4-30.

3 Move the A/C head with the X value adjustment gear

driver by the method shown in Figure 4-33, and adjust the A/C head so as to get the maximum ATR signal waveform. (Note: At this time adjust so as to get the maximum ATR signal waveform nearest the A/C head position which has been set in case of X value rough adjustment as stated in 4-17, 3- 2.)

4 Adjust the playback switching point (Refer to the

electric adjustment method.)

5 Playback the self-picture-recorded tape, and check

the flatness of ATR signal waveform and sound.

Supply side guide roller rotated in counterclockwise direction (raises guide roller) to make the tape float above the helical lead. The supply side guide roller is then rotated in the clockwise direction to flatten the ATR signal.

Take-up side guide roller rotated in counterclockwise direction (raises guide roller) to make the tape float above the helical lead. The take-up side guide roller is then rotated in the clockwise direction to flatten the ATR signal.

Notes:

When the A/C head X value adjustment is performed, be sure to perform at first X value rough adjustment (refer to 4- 17, 3-2).

Figure 4-31.

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

4-18 REPLACEMENT OF THE CAPSTAN D.D.

(DIRECT DRIVE) MOTOR

• Remove the mechanism from the set.

4-19 REPLACEMENT OF DRUM D.D. MOTOR

1. Set the ejection mode.

2. Withdraw the main power plug from the socket.

• Removal (Follow the order of indicated numbers.)

1. Unsolder loading motor wire and drum FFC (except for VC-A50S).

2. Remove the reel belt 1.

3. Remove the three screws 2.

• Reassembly

Mainchassis

• Removal (Perform in numerical order.)

1. Disconnect the FFC cable 1.

2. Unscrew the D.D. stator assembly fixing screws 2.

3. Take out the D.D. stator assembly 3.

4. Unscrew the D.D. rotor assembly fixing screws 4.

5. Take out the D.D. rotor assembly 5.

Notes:

1. In removing the D.D. stator assembly, part of the drum earth spring pops out of the pre-load collar. Be careful not to lose it.

2. Install, so that the D.D. rotor ass'y and upper drum ass'y mounting direction check holes align. (Align the upper drum dent with the rotor hole.)

3. Be careful not to damage the upper drum or the video head.

4. Protect the hole elements from shock due to contact with D.D. stator or D.D. rotor ass'y.

5. After installation adjust the playback switching point for adjustment of servo circuit.

D.D.stator ass'y

Solder loading motor wire

Capstan D.D. motor

Solder drum FFC

Reel belt

Figure 4-32.

1. Taking care so that the capstan shaft does not contact the mechanism chassis, set its position on the mechanism chassis, and then install with the three screws.

2. Install the reel belt.

3. Solder loading motor wire and insert drum FFC (except for VC-A50S).

Notes:

1. After installing the capstan D.D. motor, be sure to rotate the capstan D.D. motor and check the movement.

2. Set the tape, and check for the tape crease near the reverse guide in the playback mode. Adjust the A/C head and azimuth as stated in 4-17 item 2.

Figure 4-33.

D.D. rotor ass'y

Upper drum

FFC

4-20 REPLACING THE UPPER AND LOWER

DRUM ASSEMBLY

• Replacement (Perform in the numerical order) 1 Remove the motor as stated in 4-19 D.D. motor replace-

ment.

2 Remove the drum earth brush ass’y 2. 3 Remove the upper and lower drum assembly from main

chassis 1.

4 Remove the drum FFC holder 3.

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

4-21 ASSEMBLING OF PHASE MATCHING

MECHANISM COMPONENTS

• Assemble the phase matching mechanism components in the following order.

1. Assemble the reverse guide lever and pinch drive cam.

2. Mounting the shifter (on the back of the mechanism chassis).

3. Mounting the master cam (on the back of the mechanism chassis).

4. Assemble synchro gear.

5. Assemble the loading motor parts.

[Cares when replacing the drum]

1. Be careful so that the drum earth brush is not lost.

2. Do not touch directly the drum surface.

3. Fit gently the screwdriver to the screws.

4. Since the drum assembly is an extremely precise assembly, it must be handled with utmost care.

5. Make sure that the drum surface is free from dust, dirt and foreign substances.

6. After replacing the drum be sure to perform the tape running adjustment. After that, perform also the electrical adjustment.

• Playback switching point adjustment

• X-position adjustment and check

• Standard and x-3 slow tracking adjustment

7. After replacing the drum clean the drum.

• PINCH DRIVE CAM AND REVERSE GUIDE LEVER ASSEMBLING METHOD.

(Place the following parts in position in numerical order.)

(1)Pinch drive cam 1 (2)Reverse guide spring 2 (3)Reverse guide lever ass’y 3 (4)Open guide 4

Insert it into the groove of the shaft

Don't run up on the spring

Dot A

Dot B

Lower drum bottom side

Figure 4-34.

Figure 4-35.

Synchro gear

From Top View

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

4-22 INSTALLING THE SHIFTER

Capstan D.D. motor

(Bottom side of mechanism chassis)

Drum

1. Make sure that the loading arm T and S are at the PhaseMatching point as shown below .

2. Fix the shifter position setting part to the roading arm T position setting part as shown in figure .

3. Make sure tension arm not run on the shifter as shown in figure .

Figure 4-36.

Loading arm (T)

Shifter

Insert point

Loading arm (T)

Phase matting

Loading arm (S)

*Not run on the

sifter.

Sifter

Tension arm

Figure 4-37.

4-23 INSTALLING THE MASTER CAM (AT

REAR SIDE OF MECHANISM CHASSIS)

1. Make sure beforehand that the shifter is at initial position. (Right side from bottom view)

2. Place the master cam in the position as shown below.

3. Fix the E ring.

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

4-24 REPLACEMENT OF LOADING MOTOR

• Removal

Apply grease

*Apply grease to

the tip as well.

E-ring

Figure 4-38-1.

4. Adjust the master cam and pinch drive cam, fix the synchro gear in correct position.

Note:

See the figure below for the phase matching between the master cam synchro gear and pinch drive cam.

Apply grease

Leading connect gear.

Apply grease

Worm wheel gear.

Apply grease

L-M-Block.

Figure 4-39.

Worm gear

Red

motor.

Wire + : Red

- : White

Insert

Synchro gear

Phase matching

Pinch Drive Cam

Hole of Pinch Drive Cam

Figure 4-38-2.

Master Cam

• Replacement

Remove the loading motor, and install the replacement loading motor as shown below.

Worm gear

Loading motor

To press the motor in, first receive it by portion A.

6.95 mm

-0.15

A part

Figure 4-40.

The loading motor pressing-in must be less than 196N (20 kgf). Adjust the distance between motor and pulley to 6.95

+0. 2

mm.

–0.15

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

4-25 ASSEMBLY OF CASSETTE HOUSING

1. Proof lever Proof lever spring and Holder R

*Proof lever spring fixing direction designated.

2. 0pen lever, Sensor Plate and Frame R

MSPRD0215AJFJ

Figure 4-41.

Take care that not to damage this parts.

3. Spring to Drive Arm R

MSPRD0212AJFJ

out side

top

out side

inside

bottom

Figure 4-42.

Figure 4-43.

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