Jvc MXGA 8 UM Service Manual
This is the 59 pages manual for Jvc MXGA 8 UM Service Manual.
Read or download the pdf for free. If you want to contribute, please upload pdfs to audioservicemanuals.wetransfer.com.
Extracted text from Jvc MXGA 8 UM Service Manual (Ocr-read)
Page 1
1-2 (No.MB080) SPECIFICATION Design and specifications are subject to change without notice. Amplifier section Output Power SUBWOOFERS 120 W per channel, min. RMS, driven into 6 Ω at 63 Hz with no more than 10% total harmonic distortion. MAIN SPEAKERS 60 W per channel, min. RMS, driven into 4 Ω at 1 kHz with no more than 10% total harmonic distortion. Audio input sensitivity/ Impedance (at 1 kHz, measured at MAIN SPEAKERS)AUX 400 mV/50 kΩ Speakers/Impedance Subwoofers 6 Ω - 16 Ω Main speakers 4 Ω - 8 Ω Tuner FM tuning range 87.50 MHz - 108.00 MHz AM tuning range 530 kHz - 1 710 kHz CD player CD Capacity 3 CDs Dynamic range 85 dB Signal-to-noise ratio 85 dB Cassette deck Frequency response Normal (type I)50 Hz - 14 000 Hz Wow and flutter 0.15% (WRMS) General Power requirement AC 120 V , 60 Hz Power consumption 160 W (at operation) 18 W (on standby) Dimensions (approx.) 270 mm × 317 mm × 453 mm (W/H/D) Mass (approx.) 8.8 kg Speaker section Type 3-way bass-reflex type Speaker units Subwoofer 13.5 cm cone ×1 Main Woofer 16 cm cone ×1 Tweeter 5 cm cone ×1 Power handling capacity Subwoofer 120 W Main speaker 60 W Impedance Subwoofer 6 Ω Main speaker 4 Ω Frequency range Subwoofer 30 Hz - 70 Hz Main speaker 70 Hz - 20 000 Hz Sound pressure level Subwoofer 73 dB/W ·m Main speaker 86 dB/W ·m Dimensions (approx.) 290 mm × 317 mm × 336 mm (W/H/D) Mass (approx.) 5.5 kg each
Page 2
(No.MB080)1-3 SECTION 1 PRECAUTION 1.1 Safety Precautions (1) This design of this product contains special hardware and many circuits and components specially for safety purpos- es. For continued protection, no changes should be made to the original design unless authorized in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Services should be per- formed by qualified personnel only. (2) Alterations of the design or circuitry of the product should not be made. Any design alterations of the product should not be made. Any design alterations or additions will void the manufacturers warranty and will further relieve the manufacture of responsibility for personal injury or property damage resulting therefrom. (3) Many electrical and mechanical parts in the products have special safety-related characteristics. These characteris- tics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by us- ing replacement components rated for higher voltage, watt- age, etc. Replacement parts which have these special safety characteristics are identified in the Parts List of Ser- vice Manual. Electrical components having such features are identified by shading on the schematics and by ( ) on the Parts List in the Service Manual. The use of a substitute replacement which does not have the same safety charac- teristics as the recommended replacement parts shown in the Parts List of Service Manual may create shock, fire, or other hazards. (4) The leads in the products are routed and dressed with ties, clamps, tubings, barriers and the like to be separated from live parts, high temperature parts, moving parts and/or sharp edges for the prevention of electric shock and fire hazard. When service is required, the original lead routing and dress should be observed, and it should be confirmed that they have been returned to normal, after reassem- bling. (5) Leakage shock hazard testing After reassembling the product, always perform an isola- tion check on the exposed metal parts of the product (an- tenna terminals, knobs, metal cabinet, screw heads, headphone jack, control shafts, etc.) to be sure the product is safe to operate without danger of electrical shock.Do not use a line isolation transformer during this check. - Plug the AC line cord directly into the AC outlet. Using a "Leakage Current Tester", measure the leakage current from each exposed metal parts of the cabinet, particular- ly any exposed metal part having a return path to the chassis, to a known good earth ground. Any leakage cur- rent must not exceed 0.5mA AC (r.m.s.). - Alternate check method Plug the AC line cord directly into the AC outlet. Use an AC voltmeter having, 1,000Ω per volt or more sensitivity in the following manner. Connect a 1,500Ω 10W resistor paralleled by a 0.15µF AC-type capacitor between an ex- posed metal part and a known good earth ground. Measure the AC voltage across the resistor with the ACvoltmeter. Move the resistor connection to each exposed metal part, particularly any exposed metal part having a return path to the chassis, and measure the AC voltage across the resistor. Now, reverse the plug in the AC outlet and repeat each measurement. Voltage measured any must not exceed 0.75 V AC (r.m.s.). This corresponds to 0.5 mA AC (r.m.s.). 1.2 Warning (1) This equipment has been designed and manufactured to meet international safety standards. (2) It is the legal responsibility of the repairer to ensure that these safety standards are maintained. (3) Repairs must be made in accordance with the relevant safety standards. (4) It is essential that safety critical components are replaced by approved parts. (5) If mains voltage selector is provided, check setting for local voltage. 1.3 Caution Burrs formed during molding may be left over on some parts of the chassis. Therefore, pay attention to such burrs in the case of pre- forming repair of this system. 1.4 Critical parts for safety In regard with component parts appearing on the silk-screen printed side (parts side) of the PWB diagrams, the parts that are printed over with black such as the resistor ( ), diode ( ) and ICP ( ) or identified by the " " mark nearby are critical for safety. When replacing them, be sure to use the parts of the same type and rating as specified by the manufacturer. (This regulation dose not Except the J and C version) Good earth groundPlace this probe on each exposed metal part. AC VOLTMETER (Having 1000 ohms/volts, or more sensitivity) 1500 10W 0.15 F AC TYPE