Akai AC 3800 Service Manual

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AKAI STEREO HI-FI MUSIC CENTER

MODEL AC-3800

A150 APPLICABLE TO MODEL AC-3800L

SECTION 1 SERVICE MANUAL ....... ..... .. 1
SECTION 2 PARTS LIST .................... 41,
SECTION 3 SCHEMATIC DIAGRAM ...... 64'»

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SECTION 1

SERVICE MANUAL

TABLE OF CONTENTS

I. TECHNICAL DATA ..................................... 2
II. DISMANTLING 0F UNIT ................................. 4
III. CONTROLS .......................................... 6
IV PRINCIPAL PARTS LOCATIONS ........................... 10
V OPERATING PRINCIPLES OF VARIOUS CIRCUITS .............. 12
1, DIFFERENTIAL PEAK DETECTOR ....................... l2
2. VARACTOR TUNER AND PRESET TUNING SYSTEM .......... 13
VI. LEVEL DIAGRAM ..................................... 16
VII. TUNER ADJUSTMENT .................................. 17
1. FM TUNER SECTION ADJUSTMENT FOR
MODEL ACA3800 AND AC-3800L ........... 18
2. MW TUNER SECTION ADJUSTMENT FOR
MODEL AC-3800 ....................... 19
3. LW, MW TUNER SECTION ADJUSTMENT FOR
MODEL AC-3800L ...................... 20
VIII. TUNING CORD THREADING .............................. 21
IX. CASSETTE RECORDER MECHANISM ADJUSTMENT ............. 22
1. TAKE-UP TORQUE AT VARIOUS MODES AND
TORQUE MEASURING METHOD ........... 22
2. TAPE SPEED ADJUSTMENT ............................ 22
3. PINCH ROLLER PRESSURE MEASUREMENT ................ 22
4. ADJUSTMENT OF GAP BETWEEN THE PINCH ROLLER ARM
AND STOPPER ........................ 22
5. FLYWHEEL THRUST LOOSE PLAY ADJUSTMENT ............ 23
X. CASSETTE RECORDER HEAD ADJUSTMENT .................. 24
XI. CASSETTE RECORDER'AMPLIFIER ADJUSTMENT ............. 25
XII. TURN TABLE SECTION ADJUSTMENT ...................... 27
1. RETURN POSITION ADJUSTMENT ....................... 27
2. OVERHANG ADJUSTMENT ............................. 27
3, STYLUS PRESSURE ADJUSTMENT ....................... 27
XIII. DC RESISTANCE OF VARIOUS COILS ....................... 28
XIV. CLASSIFICATION OF VARIOUS P.C BOARDS ................. 28

For basic adjustments measuring methods. and operating principles. refer to GENERAL
OPERATING PRINCIPLES AND ADJUSTMENTS.

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XIII. DC RESISTANCE OF

VARIOUS COILS

Part Designation DC Resistance
Recording/Playback Head HN424522 7 160 ohms
i777 77777 I; also Head BF168-3o 4.7 ohms
PlungerNSolenoid I P-14W 47 ohms

Chart 5

XIV. CLASSIFICATION OF VARIOUS P.C BOARDS

14 RELATION OF P.C BOARD TITLE AND IDENTIFICATION NUMBER

PIC Board Number of P.C Board
Tone Control, Rec/PB Amp P.C Board AC»3501A
LED P.C Board AC-3SOIB
Lamp BC Board (A) AC-3501C
riamp P.C Board (B) AC-3501D
I-Ieadphone PrC Board AC-3501E
Beat Switch Pic Board AC-350lF
Multi Function P.C Board AC-3801A
Power Supply, Sys. Con and OSC P.C Board AC-3503
Main Amp P.C Board AC-3SO4
Touch SW P.C Board AC-3802
IC PIC Board AC-3803
Volume PrC Board AC-3804
Vari Con P.C Board . AC-3801B
Mme Switch P.C Board T4-8938

Chart 6

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9. ILLUSTRATION 0F TURN TABLE BLOCK (1)

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