Sony sa wm 250 service manual
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2 1.5 k Ω 0.15 µF AC voltmete r (0.75 V) To Exposed Metal Parts on Set Earth Ground SAFETY CHECK-OUT After correcting the original service problem, perform the follow- ing safety check 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 TEST 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 indica- tion is 0.75 V, so analog meters must have an accurate low- voltage scale. The Simpson 250 and Sanwa SH-63Trd are ex- amples of a passive VOM that is suitable. Nearly all battery operated digital multimeters that have a 2 V AC range are suit- able. (See Fig. A) 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.ATTENTION AU COMPOSANT AYANT RAPPORT À LA SÉCURITÉ!! LES COMPOSANTS IDENTIFIÉS PAR UNE MARQUE 0 SUR LES DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT. NE REMPLACER CES COMPOSANTS QUE PAR DES PIÈCES SONY DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU DANS LES SUPPLÉMENTS PUBLIÉS PAR SONY. TABLE OF CONTENTS 1. GENERAL Location of Controls ................................................................ 3 2. DIAGRAMS 2-1. Note for Printed Wiring Boards and Schematic Diagrams ............................................................ 3 2-2. Circuit Boards Location ...................................................... 3 2-3. Printed Wiring Boards – Main Section – ............................ 4 2-4. Printed Wiring Board – Input Control Section – ................. 5 2-5. Printed Wiring Boards – Power Section – ........................... 6 2-6. Schematic Diagram – Main Section – ................................. 7 2-7. IC Block Diagram ............................................................... 8 3. EXPLODED VIEWS 3-1. Main Section ....................................................................... 9 4. ELECTRICAL PARTS LIST ......................................... 10 SA-WM250 - UNLEADED SOLDER Boards requiring use of unleaded solder are printed with the lead- free mark (LF) indicating the solder contains no lead. (Caution: Some printed circuit boards may not come printed with the lead free mark due to their particular size.) : LEAD FREE MARK Unleaded solder has the following characteristics. -Unleaded solder melts at a temperature about 40°C higher than ordinary solder. Ordinary soldering irons can be used but the iron tip has to be applied to the solder joint for a slightly longer time. Soldering irons using a temperature regulator should be set to about 350°C. Caution: The printed pattern (copper foil) may peel away if the heated tip is applied for too long, so be careful! -Strong viscosity Unleaded solder is more viscous (sticky, less prone to flow) than ordinary solder so use caution not to let solder bridges occur such as on IC pins, etc. -Usable with ordinary solder It is best to use only unleaded solder but unleaded solder may also be added to ordinary solder. (Fig. A)
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33 SA-WM250 2-1. NOTE FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS CONTROL board POWER TRANS boar d SWITCH board INPUT CONTROL board MAIN board 2-2. CIRCUIT BOARDS LOCATION SECTION 2 DIAGRAMS SECTION 1 GENERAL LOCATION OF CONTROL This section is extracted from instruction manual. INPUT SPEAKER IN IN OUT INPUT L SPEAKER L R R Amplifier This subwoofer IN OUT L SPEAKER L R R SPEAKER This subwoofer IN OUT L SPEAKER L R R Front Speaker (R) Front Speaker (L) SPEAKER A IN OUT L SPEAKER L R R SPEAKER B A 1 B 21 C 2 LEVELPHASE E POWER 1 F Amplifier This subwooferMONO OUT INPUT D CUT OFF FREQFront Speaker (R) Front Speaker (L)Amplifier This subwoofer Amplifier CUT OFF FREQ 200Hz NORMAL REVERSE 50Hz PHASE MAX MIN LEVEL IN OUT L L R R 4 3 2 1 50Hz200Hz 75Hz 120Hz150Hz 100Hz 2 G Foot pads POWER indicator Precautions On safety-Before operating the subwoofer, be sure that the operating voltage of your subwoofer is identical with that of your local power supply. -Unplug the subwoofer from the wall outlet if it is not to be used for an extended period of time. To disconnect the cord, pull the cord by grasping the plug. Never pull the cord itself. -Should any liquid or solid object fall into the subwoofer, unplug the subwoofer and have the subwoofer checked by qualified personnel before operating it any further. -AC power cord must be changed only at the qualified service shop. When turning on or off an amplifier or other equipment Lower the volume of the amplifier to minimum.To avoid damaging the subwoofer-Be careful in setting the volume control of the amplifier to avoid an excessive input power. -Do not attempt to open the enclosure or remold speaker units and networks. In case color irregularity is observed on the nearby TV screen With the magnetically shielded type of the speaker system, the speakers can be installed near a TV set. However, color irregularity may still be observed on the TV screen depending on the type of your TV set. If color irregularity is observed...tTurn off the TV set once, then turn it on after 15 to 30 minutes. If color irregularity is observed again...tPlace the speakers further apart from the TV set.When howling occursRelocate the speaker or turn down the volume of the amplifier. On installation-Do not install the subwoofer near heat sources such as radiators or air ducts, or in a place subject to direct sunlight, excessive dust, mechanical vibration or shock. -Good ventilation is essential to prevent internal heat build-up in the subwoofer. Place the subwoofer in a location with adequate air circulation. Do not place the subwoofer on a soft surface. - Use caution when placing the speaker on a specially treated (waxed, oiled, polished, etc.) floor, as staining or discoloration may result. On cleaning the cabinetClean the cabinet with a soft cloth lightly moistened with water. Do not use any type of abrasive pad, scouring powder or solvent such as alcohol or benzine. If you have any questions or problems concerning your subwoofer that is not covered in this manual, please consult your nearest Sony dealer. Installation Since the human ear cannot detect the direction and position where the bass sound being reproduced by a subwoofer (below 200 Hz) comes from, you can install the subwoofer wherever you like in your room. To obtain a better bass reproduction, we recommend you to install the subwoofer on a solid floor where the resonance is unlikely to occur. Notes-Always install the subwoofer vertically, keeping a few centimeters away from the wall. -Do not place an object on the subwoofer or sit on it. -If the subwoofer is installed in the center of a room, the bass could be extremely weakened. This is due to the influence of the standing wave of the room. If this happens, move the subwoofer away from the center of a room or eliminate the cause of the standing wave, by installing a bookshelf on the wall, etc. Hooking Up the System OverviewUse the INPUT jacks or the SPEAKER IN terminals of the subwoofer when you connect the amplifier. -If your amplifier has one of the following types of output jacks, connect the INPUT jack and the amplifier's jack using the supplied audio connecting cord. -MONO OUT jack -MIX OUT jack -SUBWOOFER output jack(s) -SUPER WOOFER output jack(s) -If your amplifier does not have the above mentioned output jacks, connect the speaker terminals of the amplifier to the SPEAKER IN terminals instead. (A) Before you get started-Turn off the power of the amplifier and the subwoofer before making any connection. -Use the audio connecting cords that are supplied to the respective equipment. If there are not enough audio connecting cords to make the necessary connections, you need to purchase some optional audio connecting cords. -Be sure to make connections firmly to avoid noise. -Connect the AC power cord from the subwoofer to a wall outlet. -You cannot connect the CENTER output jack for use with Dolby Pro Logic function to the subwoofer. Bass sound is not output with some Dolby Pro Logic modes. Connecting to an amplifier with a single set of speaker terminals (B) If your amplifier is equipped with a single set of speaker terminals, connect the subwoofer to the amplifier, and then connect the front speakers to the subwoofer. Hookups 1 Connect the subwoofer to the amplifier. Connect the SPEAKER IN terminals of the subwoofer to the amplifiers speaker terminals with the speaker cords. Be sure to connect both L and R channels. 2 Connect the front speakers to the subwoofer. Connect the speakers to the SPEAKER OUT terminals of the subwoofer. Connecting to an amplifier with double (A+B) sets of speaker terminals (C) If your amplifier has double (A+B) sets of speaker terminals, connect both the subwoofer and the front speakers to the amplifier. Hookups 1 Connect the front speakers to the amplifier. Connect the speakers to your amplifiers SPEAKER A terminals. 2 Connect the subwoofer to the amplifier. Connect the SPEAKER IN terminals of the subwoofer to the amplifiers SPEAKER B terminals using the supplied speaker cords. When using the double (A+B) sets of speakers, make sure that you select the A+B position with your amplifier. NoteWhen you are using SPEAKER A terminal (front speaker) only or when the power of the amplifier is turned off, turn down the volume or turn off the power of the subwoofer. Otherwise, hum noise may be heard. Connecting to an amplifier with a special jack for a subwoofer If your amplifier has a special jack for a subwoofer (such as MONO OUT jack, MIX OUT jack, SUBWOOFER jack or SUPER WOOFER jack), connect the INPUT jack of the subwoofer to one of those jacks. Hookups (D) Connect the MONO OUT jack of your amplifier to the INPUT jack of the subwoofer with the supplied audio connecting cord. NoteIf the output level of your amplifier is not large enough, the sound may not be loud enough. In this case, connect the speaker terminals of the amplifier directly to the SPEAKER IN terminals of the subwoofer. Connecting the AC power cord-Connect the AC power cord from the subwoofer and from your amplifier to a wall outlet. -Make sure that power to the subwoofer is turned off before you plug in or unplug any power cord. Listening to the Sound ( E) 1 Turn on the amplifier and select the program source. 2 Press POWER. The subwoofer turns on and the POWER indicator lights up in green. 3 Play the program source. Adjust the VOLUME so that sound from the front speakers is not distorted. If it is distorted, the sound from the subwoofer will also be distorted. Notes-Never set the amplifiers tone control (BASS, TREBLE, etc.) or the equalizer output to a high level or input sinewaves of 20 Hz to 50 Hz recorded on a commercially-available test disc or special sound (bass sound of electronic musical instrument, pop noise of analog disc turntable, sound with abnormally enhanced bass, etc.) in a high level to this unit. These actions may cause damage to the speakers. When a special disc containing abnormally enhanced bass is played, noise may be output in addition to the original sound. In such a case, reduce the sound level. -The subwoofer output signal (DOLBY digital signal) of the digital surround processor sold singularly is set 10 dB higher by Dolby laboratories Licensing Corporation. In the case of using normally, adjust the subwoofer level. Adjusting the Sound (F) You can adjust the sound of the subwoofer to suit the sound of your front speakers. Reinforcing the bass sound gives you a greater sense of atmosphere. 1 Adjust the cut-off frequency. Turn the CUT OFF FREQ control, depending on the reproduction frequencies of your front speakers. Refer to the following when adjusting. 1Typical very small sized speakers: 5 – 7 cm dia. 2Typical small sized speakers: 8 –15 cm dia. 3Typical medium sized speakers: 16 –24 cm dia. 4Typical large sized speakers: more than 25 cm dia. To make the most of the low level converter function of Dolby digital, turn the CUT OFF FREQ as high as possible when playing back the Dolby digital. 2 Adjust the volume level of the subwoofer. Turn the LEVEL control so that you can hear the bass sound a little more than before. To increase the volume, turn the LEVEL control clockwise. To reduce the volume, turn the LEVEL control counterclockwise. 3 Play your favorite song and movie. Male vocal tunes and voice containing bass sounds are most suitable for adjustment. Turn the volume for front speakers to the same level as usual. 4 Select the phase polarity. Use the PHASE selector to select the phase polarity. 5 Repeat steps 1 to 4 to adjust for your preference. Once you have adjusted the subwoofer to the settings you want, use the VOLUME control on the amplifier to adjust the volume of the subwoofer with that of the other speakers. You dont need to adjust the subwoofer settings when you change the volume level of the amplifier. Notes-If the sound distorts when you turn on the bass reinforcement from your amplifier (such as, DBFB, GROOVE, the graphic equalizer, etc.), turn off the bass reinforcement and adjust the sound. -Do not turn the volume of the subwoofer to maximum. Doing so may weaken the bass sound. Moreover, extraneous noise may be heard. -Selecting NORMAL or REVERSE with the PHASE selector reverses the polarity and may provide better bass reproduction in certain listening environments (depending on the type of front speakers, the position of the subwoofer and the adjustment of the cut-off frequency). It may also change the expanse and tightness of sound, and effect the feeling of the sound field. Select the setting that provides the sound you prefer when listening in your normal listening position. Setting the speaker ( G) To prevent speaker vibration or movement while listening, attach the supplied foot pads to the speaker. THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS. (In addition to this, the necessary note is printed in each block.) For schematic diagrams. Note: -All capacitors are in µF unless otherwise noted. pF: µµF 50 WV or less are not indicated except for electrolytics and tantalums. -All resistors are in Ω and 1/4 W or less unless otherwise specified. - f : internal component. -C: panel designation. For printed wiring boards.Note: -X: parts extracted from the component side. -Y: parts extracted from the conductor side. - : Pattern from the side which enables seeing. -Abbreviation CND : Canadian model. MY : Malaysia model. SP : Singapore model. -A: B+ Line. -B: B– Line. -Voltages are dc with respect to ground under no-signal (detuned) conditions. no mark : Power on -Voltages are taken with a VOM (Input impedance 10 MΩ). Voltage variations may be noted due to normal produc- tion tolerances. -Signal path. F: AUDIO -Abbreviation CND : Canadian model. MY : Malaysia model. SP : Singapore model. TW : Taiwan model. Note: The components identi- fied by mark 0 or dotted line with mark 0 are criti- cal for safety. Replace only with part number specified.Note: Les composants identifiés par une marque 0 sont critiques pour la sécurité. Ne les remplacer que par une piéce portant le numéro spécifié.