SONY SONY SA-WM20 ACTIVE SUBWOOFER. free download

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SA-WM20 SERVICE MANUAL Ver.1.0 2001.1 US Model Canadian Model AEP Model UK Model E Model SPECIFICATION System Type Active Subwoofer (magnetically shielded design) General Power requirements Canadian model: 120 V AC, 60 Hz European model: 230 V AC, 50/60 Hz Speaker unit Woofer: 20 cm dia. (8 in.), cone type Power consumption 50 W Amplifiersection Continuous RMS output : Canadian model (0.8%) 50W European model (DIN) 50 W Other models (0.8%) 50 W Dimensions Approx. 270 x 325 x 385 mm (10 3/ 4 x 12 7/ 8 x 15 1/ 4 in.) (w/h/d) Mass 10 kg (22 lb 1oz) Reproduction frequency range 28 Hz ­ 200 Hz Supplied accessories Foot pads (4) Audio connecting cord (1 phono plug ­ 1 phono plug), 2 m (6 ft 6 1/ 2 in.) (1) Speaker cords, 2.5 m (8 ft 2 1/ 2 in.) (2) Design and specifications are subject to change without notice. High frequency cut-off frequency 50 Hz ­ 200 Hz Phase selector NORMAL, REVERSE Inputs Input jacks LINE IN: input pin jack SPEAKER IN: input terminals Output jacks SPEAKER OUT: output terminals ACTIVE SUBWOOFER 9-873-806-11 2001A0900-1 © 2001. 1 Sony Corporation Audio Entertainment Group General Engineering Dept. 1 SA-WM20 SAFETY CHECK-OUT (US model) 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. TABLE OF CONTENTS 1. GENERAL ... 3 2. DIAGRAMS 2-1. Circuit Boards Location ... 3 2-2. Printed Wiring Board ... 4 2-3. Schematic Diagram ... 5 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. A battery-operated AC milliammeter. The Data Precision 245 digital multimeter is suitable for this job. 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) 3. EXPLODED VIEW 3-1. Front Section ... 6 3-2. Amp Section ... 6 4. ELECTRICAL PARTS LIST ... 7 2