Sharp VC-A50 User Manual

1
VC-A10/A10S/A500
VC-A50/A50S/A50SB
VC-A60/A75/A80S
VIDEO CASSETTE PLAYER
VC-A10/A10S/A50/A50S/
A50S(B)/A60/A75/A80S
VC-A500
SERVICE MANUAL
CONTENTS
Page
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
SHARP CORPORATION
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.
VC-A10/A10S
VC-A50/A50S/A50S(B)
VC-A500
VC-A60
VC-A75
VC-A80S
S62L3VC-A10//

Sharp VC-A50 Specifications

General

Audio	Mono
Tuner	Yes
Remote Control	Yes
Recording Speed	SP, LP
Playback Speed	SP, LP
Connections	Composite Video, Audio
Inputs	Composite Video, Audio
Outputs	Composite Video, Audio

Summary

1. SPECIFICATIONS

PRECAUTIONS IN PART REPLACEMENT

Safety precautions for part replacement during servicing.

2. DISASSEMBLY AND REASSEMBLY

4. ADJUSTMENT, REPLACEMENT AND ASSEMBLY OF MECHANICAL UNITS

4-1 MECHANISM CONFIRMATION ADJUSTMENT JIG

Details special jigs required for mechanism confirmation and adjustment.

4-6 CHECKING AND ADJUSTMENT OF TAKE-UP TORQUE IN FAST FORWARD MODE

4-7 CHECKING AND ADJUSTMENT OF TAKE-UP TORQUE IN REWIND MODE

4-8 CHECKING AND ADJUSTMENT OF TAKE-UP TORQUE IN RECORD/PLAYBACK MODE

4-9 CHECKING AND ADJUSTMENT OF TAKE-UP TORQUE IN VIDEO SEARCH REWIND MODE

4-10 CHECKING THE VIDEO SEARCH REWIND BACK TENSION

4-13 CHECKING AND ADJUSTMENT OF RECORD/PLAYBACK BACK TENSION

4-14 CHECKING THE BRAKE TORQUE

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

Steps for replacing the Audio/Control (A/C) head assembly.

4-17 ADJUSTMENT OF TAPE DRIVE TRAIN

Steps for adjusting the tape drive train for optimal performance.

4-18 REPLACEMENT OF THE CAPSTAN D.D. MOTOR (DIRECT DRIVE)

4-19 REPLACEMENT OF DRUM D.D. MOTOR

4-20 REPLACING THE UPPER AND LOWER DRUM ASSEMBLY

5. ELECTRICAL ADJUSTMENT

ADJUSTMENT OF HEAD SWITCHING POINT

6. MECHANISM OPERATION FLOWCHART AND TROUBLESHOOTING GUIDE

7. TROUBLESHOOTING

1. FF/REW FAILURE (NO TAPE WINDING)

Troubleshooting steps for FF/REW failure without tape winding.

2. REC/PLAY FAILURE (MODE RELEASE)

Troubleshooting for REC/PLAY failure with mode release issues.

3. WINDING FAILURE AT VSR

Troubleshooting for winding failures occurring at VSR mode.

4. UNUSUAL SOUND IN EACH MODE

Diagnosing and resolving unusual sounds in various operating modes.

4-ii) Unusual sound in FF/REW mode

Troubleshooting unusual sounds specifically during FF/REW mode.

FLOW CHART NO.1 POWER TROUBLESHOOTING(1)

Power troubleshooting flowchart for initial power issues.

FLOW CHART NO.2 POWER TROUBLESHOOTING(2)

Further power troubleshooting steps for fuse blown issues.

FLOW CHART NO.3 POWER TROUBLESHOOTING(3)

Power troubleshooting flowchart for abnormal noise or sound.

FLOW CHART NO.4 POWER TROUBLESHOOTING(4)

Power troubleshooting for low output voltage conditions.

FLOW CHART NO.5 SYSTEM CONTROL TROUBLESHOOTING(1)

Troubleshooting flowchart for system control issues when power is not on.

FLOW CHART NO.6 POWER TROUBLESHOOTING(6)

Power troubleshooting for low output voltage situations.

FLOW CHART NO.8 INFRARED R/C TROUBLESHOOTING

Troubleshooting for issues with the infrared remote control.

FLOW CHART NO.7 KEY CONTROL TROUBLESHOOTING(2)

Troubleshooting for key input not being received.

FLOW CHART NO.9 CASSETTE CONTROL TROUBLESHOOTING(1)

Troubleshooting for cassette loading failures.

FLOW CHART NO.10 CASSETTE CONTROL TROUBLESHOOTING(2)

Troubleshooting for cassette taken in but ejected immediately.

FLOW CHART NO.11 LOADING MOTOR AND EJECT TROUBLESHOOTING

Troubleshooting for loading motor and eject mechanism failures.

FLOW CHART NO.12 CAPSTAN MOTOR TROUBLESHOOTING

Troubleshooting steps when the capstan motor fails to run.

FLOW CHART NO.13 DRUM MOTOR TROUBLESHOOTING(1)

Troubleshooting for drum motor failure to run.

FLOW CHART NO.14 DRUM MOTOR TROUBLESHOOTING(2)

Troubleshooting for drum motor running only briefly.

FLOW CHART NO.15 HEAD SWITCHING PULSE TROUBLESHOOTING.

Troubleshooting for missing head switching pulses.

FLOW CHART NO.16 DRUM SERVO TROUBLESHOOTING

Troubleshooting when the drum servo function is not operating.

FLOW CHART NO.17 CAPSTAN SERVO TROUBLESHOOTING

Troubleshooting for capstan servo malfunctions.

FLOW CHART NO.18 E-E MODE TROUBLESHOOTING

Troubleshooting for no picture E-E signal output.

FLOW CHART NO.19 RECORDING MODE TROUBLESHOOTING

Troubleshooting for recording mode failures (luminance/chrominance).

FLOW CHART NO.20 LINEAR SOUND MODE TROUBLESHOOTING(1)

Troubleshooting for no E-E sound heard in linear mode.

FLOW CHART NO.21 LINEAR SOUND MODE TROUBLESHOOTING(2)

Troubleshooting for no linear sound recording.

FLOW CHART NO.22 LINEAR SOUND MODE TROUBLESHOOTING(3)

Troubleshooting for no linear sound playback.

8. BLOCK DIAGRAM

10. REPLACEMENT PARTS LIST