Aiwa HV-BA75, Service Manual

2

TABLE OF CONTENTS

SPECIFICATIONS

............................................................ 3

ACCESSORIES LIST

....................................................... 3

DISASSEMBLY INSTRUCTIONS

..................................... 4

SERVICE POSITION

........................................................ 5

VCR TEST TAPE INTERCHANGEABILITY TABLE

........ 6

ELECTRICAL MAIN PARTS LIST

.............................. 7 ~ 9

TRANSISTOR ILLUSTRATION

........................................ 9

WIRE HARNESS DIAGRAM

.......................................... 10

BLOCK DIAGRAM

................................................. 11 ~ 22

SCHEMATIC DIAGRAM

 1. POWER/TUNER/NICAM <7700/BA75> ............ 23 ~ 24

 2. POWER/TUNER <935> ..................................... 25 ~ 26

 3. AUDIO/VIDEO SECTION ................................... 29 ~ 30

 4. Hi-Fi AUDIO/SCART <7700/BA75> ................... 31 ~ 32

 5. SCART<935> ..................................................... 33 ~ 34

 6. SYSTEM CONTROL/SERVO <7700/BA75> ..... 35 ~ 36

 7. SYSTEM CONTROL/SERVO <935> ................. 39 ~ 40

 8. KEY1 <7700/BA75> ................................................... 47

 9. KEY2 <7700/BA75> ................................................... 47

 10. KEY1 <935> ............................................................. 49

 11. KEY2 <935> ............................................................. 49

WAVEFORM

 AUDIO/VIDEO SECTION ............................................... 28

 SYSTEM CONTROL/SERVO SECTION ....................... 38

VOLTAGE CHART

 1. POWER SECTION ..................................................... 25

 2. AUDIO/VIDEO SECTION ........................................... 27

 3. Hi-Fi AUDIO/SCART SECTION ................................. 33

 4. SYSTEM CONTROL/SERVO SECTION ................... 37

FL DISPLAY

............................................................ 41 ~ 42

WIRING

 1. MAIN C.B <7700/BA75> .................................... 43 ~ 44

 2. MAIN C.B <935> ................................................ 45 ~ 46

 3. KEY1 C.B <7700/BA75> ............................................ 48

 4. KEY2 C.B <7700/BA75> ............................................ 48

 5. KEY1 C.B <935> ........................................................ 50

 6. KEY2 C.B <935> ........................................................ 50

 7. NICAM C.B ................................................................. 51

ADJUSTMENT

........................................................ 52 ~ 53

IC DESCRIPTION

................................................... 54 ~ 57

MECHANICAL EXPLODED VIEW 1/1

........................... 58

MECHANICAL MAIN PARTS LIST  1/1

......................... 59

MECHANISM EXPLODED VIEW 1/3~3/3

.............. 60 ~ 64

MECHANISM MAIN PARTS LIST 1/3~3/3

............. 61 ~ 65

DECK MECHANISM PARTS LOCATIONS

Top View .......................................................................... 66

Bottom View .................................................................... 66

DECK MECHANISM DISASSEMBLY

  1. Drum Assembly ......................................................... 67

  2. Plate Assembly Top ................................................... 69

  3. Holder Assembly CST ............................................... 69

  4. Guide CST ................................................................ 69

  5. Bracket Side (L)/Bracket Assembly Door .................. 69

  6. Arm Assembly F/L ..................................................... 69

  7. Lever Assembly S/W ................................................. 69

  8. Arm Assembly Cleaner .............................................. 70

  9. Head F/E ................................................................... 70

 10. Base Assembly A/C Head ........................................ 70

 11. Brake Assembly S .................................................... 71

 12. Brake Assembly T .................................................... 71

 13. Arm Assembly Tension ............................................. 71

 14. Reel S & Reel T ....................................................... 71

 15. Support CST ............................................................ 72

 16. Base Assembly P4 ................................................... 72

 17. Opener Lid ............................................................... 72

 18. Arm Assembly T/up .................................................. 72

 19. Arm Assembly Pinch ................................................ 72

 20. Belt Capstan/Motor Capstan .................................... 73

 21.Clutch Assembly D33-K ............................................ 73

 22. Lever F/R ................................................................. 73

 23. Gear Assembly H-Up/D-K or

       Gear Assembly Up/D-K ............................................ 73

 24. Bracket Assembly Jog .............................................. 74

 25. Guide Rack F/L, Gear Rack F/L ............................... 74

 26. Brake Assembly Capstan ......................................... 74

 27. Gear Drive/Gear Cam/Gear Connector ................... 75

 28. Bracket Assembly L/D motor .................................... 75

 29. Gear Sector .............................................................. 76

 30. Base Tension/Plate Slider/Lever Tension ................. 76

 31. Gear Assembly P3/Gear Assembly P2 .................... 77

 32. Base Assembly P3/Base Assembly P2 .................... 77

 33. Arm Assembly Idler or Arm assembly Idler Jog ........ 77

DECK MECHANISM ADJUSTMENT

Tools and Fixtures for service ......................................... 78

 1. Mechanism Alignment Position Check ....................... 79

 2. Preparation for Adjustment ........................................ 80

 3. Checking Torque ........................................................ 80

 4. Guide Roller Height Adjustment ................................. 81

  4-1. Preliminary Adjustment .......................................... 81

  4-2. Precise Adjustment ................................................ 81

 5. Audio/Control (A/C) Head Adjustment ........................ 82

  5-1. Preliminary Adjustment .......................................... 82

  5-2. Confirm that the Tape Path smoothly between

          the Take-up Guide and Pinch Roller ..................... 83

  5-3. Precise Adjustment (Azimuth Adjustment) ............. 83

 6. X-Value Adjustment .................................................... 83

 7. Adjustment after Replacing Drum Assembly

    (Video Heads) ............................................................. 84

 8. Check the Tape Travel after Reassembling

    Deck Assembly ............................................................ 84

  8-1. Checking Audio and RF Locking Time

          during Playback and after CUE or REV ................ 84

  8-2. Check for Tape Curling or Jamming ....................... 84

MAINTENANCE/INSPECTION PROCEDURE

 1. Check before starting Repairs ................................... 85

 2. Required Maintenance ............................................... 86

 3. Scheduled Maintenance ............................................ 86

 4. Supplies Required for Inspection and Maintenance .. 86

 5. Maintenance Procedure ............................................. 86

  5-1. Cleaning ................................................................. 86

  5-2. Greasing ................................................................ 87

MECHANISM TROUBLESHOOTING GUIDE

 1. Deck Mechanism ............................................... 88 ~ 90

 2. Front Loading Mechanism ................................. 91 ~ 92