Sanyo Vizon DP32746 Service Manual

Also see for DP32746: Owner's manual Connection guide

Sanyo Vizon DP32746 Service Manual Manual pdf 2 page image

— 2 —SAFETY PRECAUTIONSWARNING: The chassis of this receiver has a floating ground with thepotential of one half the AC line voltage in respect to earth ground.Service should not be attempted by anyone not familiar with theprecautions necessary when working on this type of equipment.The following precautions must be observed:1. An isolation transformer must be connected in the power linebetween the receiver and the AC line before any service isperformed on the receiver.2. Comply with all caution and safety-related notes provided on theside of the cabinet, inside the cabinet, and on the chassis.3. When replacing a chassis in the cabinet, always be certain that allthe protective devices are installed properly, such as controlknobs, adjustment covers, shields and barriers.4. Before replacing the back cover of the set, thoroughly inspect theinside of the cabinet to see that no stray parts or tools have beenleft inside.Before returning any television to the customer, the servicetechnician must perform the following safety checks to be surethat the unit is completely safe to operate without danger ofelectrical shock.ANTENNA COLD CHECKRemove AC plug from the 120 VAC outlet and place a jumperacross the two blades. Connect one lead of an ohmmeter to thejumpered AC plug, and touch the other lead to each exposed antennaterminal (UHF and VHF antenna terminals). The resistance mustmeasure between 1M ohm and 5.2M ohm. Any resistance valuebelow or above this range indicates an abnormality which requirescorrective action.LEAKAGE CURRENT CHECKPlug the AC line cord directly into a 120 VAC outlet. (Do not use anisolation transformer for this check.) Use an AC voltmeter, that has5000 ohms per volt or more sensitivity. Connect a 1500 ohm 10 wattresistor, paralleled by a 0.15 μF 150 VAC capacitor, between aknown good earth ground (water pipe, conduit, etc.) and allexposed metal parts of the cabinet (antennas, handle bracket, metalcabinet, screw heads, metal overlays, control shafts, etc.). Measurethe AC voltage across the 1500 ohm resistor. The AC voltage shouldnot exceed 750 mV. A reading exceeding 750 mV indicates that adangerous potential exists. The fault must be located and correct-ed. Repeat the above test with the receiver power plug reversed.NEVER RETURN A RECEIVER TO THE CUSTOMER WITHOUTTAKING THE NECESSARY CORRECTIVE ACTION.PRODUCT SAFETY NOTICEW hen replacing components in a receiver, always keep in mindthe necessary product safety precautions. Pay special attentionto the replacement of components marked with a star () in theparts list and in the schematic diagrams. To ensure safe productoperation, it is necessary to replace those components with theexact same PARTS .SERVICING ELECTROSTATICALLY SENSATIVE DEVICESSemiconductors (solid-state devices) that can be damaged by staticelectricity are referred to as Electrostatically Sensitive (ES) devices.Examples of typical ES devices are: Integrated Circuits (IC), Field-Effect Transistors (FET), and “chip” components. The followingtechniques should be observed strictly, to reduce the occurrence ofsemiconductor damage due to electrostatic discharge.1. Immediately prior to handling any semiconductor component oran assembly containing a semiconductor device or devices, dis-charge the electrostatic buildup on your body by touching aknown earth ground. You may also obtain and wear a commer-cially available discharging wrist strap device.CAUTION: Be sure to remove the wrist strap before applyingpower to any unit being serviced.2. After removing an ES equipped assembly, place it on a conduc-tive surface, such as, aluminum foil, to prevent buildup orexposure to static electricity.3. Use only grounded-tip soldering irons to solder or unsolder ESdevices.4. Use only anti-static solder removal devices. Some suction-typedevices can generate static electricity adequate to damage ESdevices.5. A replacement ES device will come packaged in protective material(conductive foam, aluminum foil, or some comparable conductivematerial). Do Not remove an ES device from its protective packag-ing unless you are prepared to install it immediately.6. Precisely prior to removing an ES device from its protective pack-aging, touch the protective packaging to the chassis orassembly in which the device will be installed.CAUTION: Be sure that no power is applied to the chassis or circuitassembly.7. Incidental body movements, such as, lifting a foot from a carpetedfloor or the rubbing of fabric together can generate static electricitysufficient to damage ES devices. Therefore, minimize all bodymovements while handling exposed (unpackaged) ES devices.0.15 μF 150V AC1500 ohm10 wattGood earth groundsuch as a water pipe,conduit, etc.AC OUTLETTELEVISIONRECEIVERREADING SHOULD NOT EXCEED 750 mV.AC VOLTMETER(5000 ohms per volt or more sensitivity)To be touched to all of exposed metal parts.Voltmeter Hook-up for Leakage Current Check.SAFETY INSTRUCTIONS