Sansui AU 6600 Service Manual

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AU-6600

This service manual is designed for service engineers to repair, adjust,
maintain and order the replacement parts of the AU-6600 correctly.
when ordering the parts, use the stock number and parts name speci-
fically referring to the Parts Locations & Parts Listsi
For general usage and maintenance of the unit, please refer to the

Operating Instructions attached with the unit.

TABLE OF CONTENTS

Section Ltle Pat-gt?
1. SPECIFICATIONS ................................................ 2
2. BLOCK DIAGRAM AND EACH LEVEL ............................ 3
3. ADJUSTMENT .................................................. 4

3-1. Driver Circuit Board Adjustment .............................. 4
4. TROUBLESHOOTING CHART .................................... 5
4-1. Troubleshooting on Power Supply Section ...................... 5
4-2. Troubleshooting on Audio Section .......................... 5. 6
5. PARTS LOCATIONS AND PARTS LISTS ........................ 7
5-1. F-2092A Equalizer & Power Supply Circuit Board .............. 7, 8
5-2. F-2099 Volume Circuit Board .................................. 8
5-3. F-2412 Tone Control Circuit Board ............................ 9
5-4. F-2413 Accessory Switch Circuit Board .......................... 10
5-5. F-2097A Driver & Power Supply Circuit Board. . . .11, 12
5-6. F-2098 Accessory Switch Circuit Board ............... 13

5-7. Other Parts (Front Side)
5- B. Other Parts (Top Side).
5- 9 Other Parts (Bottom Side) .................

6. REPLACEMENT OF POWER TRANSISTORS ...................... 17
7. PACKING LIST .................................................. 17
8. ACCESSORY PARTS LIST . . 17
9. SCHEMATIC DIAGRAM .......................................... 18

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3. ADJUSTMENT

3-1. Driver Circuit Board Adjustment (See Fig. 3-1 and 3-2)

Note: Confirm the AC power supply voltage.
. MASTER VOLUME t. ,,,,,,,,,, Minimum
. SPEAKERS Selector .. . ........... A

. For adjustment, run the unit for more than 3 minutes after the power is switched ON.

1.

2

3

4. Make the SP terminals free (no load).

5

6. Room temperature should be 18~28°C (65~B3° F) for bias current adjustment.

STEP SUBIECT EQUIPMENT MEASURE OUTPUT ADIUST ADJUST FOR CONDITION
1 DC 0V Lch DC volt meter SP terminal L-ch F-2097A 0V:10mV aTurn volumes of VR03, VR04
(See Fig. 3-2) VR01 CCW
2 DC 0V R-ch Same as above SP terminal R-ch F-2097A Same as above
(See Fig. 3-2) VROZ
3 Bias current DC milliammeter F-2097A F01 F-2097A 25110mA oStep down meters range
L-ch (See Fig. 3-1) VR03 accordingly
4 Bias current Same as above F-2097A F02 F-2097A Same as above
R-ch (See Fig. 3-1) VRO4
Fig. 3-1 milliam
/ rnetere
l
milliam
/ metefig VRos.
VRM + _ + _ /
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Condition of Level Measuring

*Value of each level in block diagram was measured by
the followings.

1. MASTER VOLUME control .............. Maximum
2. BASS, MlDRANGE, TREBLE & BALANCE
volume controls .................... Center
3. TONE 8: FILTER switch control ............ IN
4. Input ............ PHONO-1 2.7mV1kHz Sine Wave

AUX-1, 2 110mV lkHz Sine Wave

(output impedance of 6000. at an
auclio oscillator)

5. Output .......... 17.9V (40W) 8.!)

Note: Each voltage value is for reference and measured
by a VTVM. In some recorders, the actual volt-
age value is in minor difference from the refer-
ence value.