Sansui AU 3900 Service Manual

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SERVICE MANUAL

INTEGRATED STEREO AMPLIFIER

SANSIJI AU-3900/4900

SANSUI ELECTRIC CO., LTD.

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This service manual is designed for service engineers to repair, adjust,

maintain and order the repIacement parts of AU-3900 and AU-49OO
correctly.

When ordering the parts, use the stock number and parts name specific-
ally referring to the Parts Location & Parts Lists.

For

general usage and maintenance of the unit, please refer to the

Operating Instructions attached with the unit.

TABLE OF CONTENTS

Section
1 .

P

Title Page
SPECIFICATIONS ................................................ 2

1-1. AU-39OO

I-2. AU-4900 2
ADJUSTMENTS .................................................. 3
2-1. Bias Current Adjustment ...................................... 3
OTHER PARTS (Top Side) ...................................... 4
OTHER PARTS (Front Side) ...................................... 5
PARTS LOCATION AND PARTS LISTS ... 6
5-1. F-2555 Tone Control Circuit Board ............................ 6
5-2. Fv2554 Driver Circuit Board .................................... 7
5-3, F-2556 Switch Circuit Board 7
5-4. F-2587 Connector Circuit Board ................................ 8
FIGURES ........................................................ 8
TROUBLESHOOTING ....................... . 8
_ 7-1. Troubleshooting Chart ........................................ 8
7'2. Operation Block Diagram .................................... 8
SCHEMATIC DIAGRAM ....................... 9
8-1. AU-39OO ................................... 9
8-2. AU-49OO ......... ' ........................................... 10
PACKING LIST .................................................. 11
ACCESSORY PARTS LIST ...................................... 11

10.