Sony str k 402 service manual

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2 STR-K402 MODEL IDENTIFICATION - BACK PANEL - AM tuner section Tuning range With 10-kHz tuning scale: 530 - 1710 kHz 4) With 9-kHz tuning scale: 531 - 1710 kHz 4) AntennaLoop antenna Intermediate450 kHz frequency Usable sensitivity 50 dB/m (at 1,000 kHz or 999 kHz) S/N54 dB (at 50mV/m) Harmonic distortion 0.5% (50mV/m, 400 kHz) Selectivity: At 9 kHz: 35 dB At 10 kHz: 40 dB 4) You can change the AM tuning scale to 9 kHz 10 kHz. After tuning in any AM station, turn off the receiver. Hold down the TUNING + button and press the button. All preset stations will be erased when you change the tuning scale. To reset the scale to 10 kHz (or 9 kHz), repeat the procedure. Video section InputsVideo: 1 Vp-p 75 ohms OutputsVideo: 1 Vp-p 75 ohms General SystemTuner section: PLL quartz-locked digital synthesizer system Preamplifier section: Low-noise NF type equalizer Power amplifier section: Pure-complementary SEPP Power requirements 120 V AC, 60 HzPower consumption 185 W In Standby Condition: 1 W Dimensions430 × 145 × 298 mm (17 7 7/8 19 5/8 in.) including projecting parts and controls Mass (Approx.) 7.2 kg (15 lb 14 oz) Supplied accessories Design and specifications are subject to change without notice.-FM wire antenna (1) -AM loop antenna (1) -R6 (size-AA) batteries (2) - Remote Commander (remote) (1)×× Parts No. MODEL PARTS No. US 4-235-014-0s

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3 STR-K402 SAFETY-RELATED COMPONENT WARNING!! COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED LINE WITH MARK 0 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. 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 microamperes). 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) SAFETY CHECK-OUT To Exposed Metal Parts on Set 0.15 µF 1.5 k-„¦AC Voltmeter (0.75 V) Earth Ground Fig. A. Using an AC voltmeter to check AC leakage. TABLE OF CONTENTS 1. GENERAL ··········································································4 2. TEST MODE ······································································6 3. DIAGRAMS 3-1. Circuit Boards Location···············································8 3-2. Block Diagram Main Section·····································9 3-3. Block Diagram Display Section·······························10 3-4. Schematic Diagram Main Section (1/3)···················11 3-5. Schematic Diagram Main Section (2/3)···················12 3-6. Schematic Diagram Main Section (3/3)···················13 3-7. Printed Wiring Board Main Section·························14 3-8. Schematic Diagram Digital Section························15 3-9. Printed Wiring Board Digital Section······················16 3-10. Schematic Diagram Display Section·······················17 3-11. Printed Wiring Board Display Section·····················18 3-12. Schematic Diagram Video Section··························19 3-13. Printed Wiring Board Power Section·······················19 3-14. Printed Wiring Board Video Section························19 3-15. IC Block Diagrams·····················································20 3-16. IC Pin Function Description······································21 4. EXPLODED VIEWS ······················································23 4-1. Front Panel Section····················································23 4-2. Chassis Section··························································24 5. ELECTRICAL PARTS LIST ·······································25