SONY TA-AV661
Service Manual

TABLE OF CONTENTS
Section Title Page

SAFETY CHECK-OUT After correcting the original service problem, perform the following safety checks before releasing the set to the customer: Check the antenna terminals, metal trim, �metallized� knobs, screws, and all other exposed metal parts for AC leakage. Check leakage as described below. LEAKAGE The AC leakage from any exposed metal part to earth ground and from all exposed metal parts to any exposed metal part having a return to chassis, must not exceed 0.5 mA (500 microampers). Leakage current can be measured by any one of three methods. 1. A commercial leakage tester, such as the Simpson 229 or RCA WT-540A. Follow the manufacturers� instructions to use these instruments. 2. A battery-operated AC milliammeter. The Data Precision 245 digital multimeter is suitable for this job. 3. Measuring the voltage drop across a resistor by means of a VOM or battery-operated AC voltmeter. The �limit� indication is 0.75 V, so analog meters must have an accurate low-voltage scale. The Simpson 250 and Sanwa SH-63Trd are examples of a passive VOM that is suitable. Nearly all battery operated digital multimeters that have a 2V AC range are suitable. (See Fig. A)

SECTION 1.GENERAL ...................................................... 3 SECTION 2. DIAGRAMS
2-1. 2-2. 2-3. 2-4. Circuit Boards Location ..................................................... 4 Printed Wiring Board � Display Section � ..................... 6 Schematic Diagram � Display Section � ........................ 9 IC Pin Function � IC401 System Control (µPD78043AGF-033-3B9) ........ 12

2-5. Schematic Diagram � Main Section � .......................... 13 2-6. Printed Wiring Board � Main Section � ....................... 17

SECTION 3. EXPLODED VIEWS
3-1. Front Panel Section .......................................................... 21 3-2. Back Panel Section ........................................................... 22 3-3. Chassis Section ................................................................. 23

SECTION 4. ELECTRICAL PARTS LIST .................. 24

SAFETY-RELATED COMPONENT WARNING !! COMPONENTS IDENTIFIED BY MARK ! OR DOTTED LINE WITH MARK ! ON THE SCHEMATIC DIAGRAMS AND IN THE PARTS LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.

To Exposed Metal Parts on Set

[Lighting of all FLs and LEDs]
While pressing 3 button, connect the power supply plug to the outlet, the FL tubes and LEDs light up.
0.15µF 1.5k AC voltmeter (0.75V)

[Key Check]
With all the FLs and LEDs lit, when the 3 button and WOOFER ON/OFF button are pressed simultaneously, �SET **� is displayed. When the 3 button and WOOFER ON/OFF button are pressed simultaneously again, the Key Check mode is set and �KEY 0� is displayed. Each time a button other than POWER is pressed, the display will count up to �KEY 30�. A button already pressed will not be counted when pressed again. When the button is pressed for the 31st time, �AMP� is displayed and the key check mode is ended. Note: The ** of �SET **� differs according to the version of the microprocessor. To exit the test mode, press the POWER button. � Abbreviation FL : Fluorescent Indicator Tube
Earth Ground

Fig. A. Using an AC voltmeter to check AC leakage.

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