Panasonic CT-36SL13G Service Manual

Also see for CT32SC13G - 32" COLOR TV-ANALOG: Operating instructions Service manual

Panasonic CT-36SL13G Service Manual Manual pdf 2 page image

General guidelinesAn isolation transformer should always be used during the servicing of a receiver whose chassisis not isolated from AC power line. Use a transformer of adequate power rating as this protectsthe technician from accidents resulting in personal injuryfrom electrical shocks. It will alsoprotect the receiver from being damaged by accidental shorting that may occur during servicing.When servicing, observe the original lead dress, especially in the high voltage circuit. Replace alldamaged parts (also parts that show signs of overheating.)Always replace protective devices, such as fish paper, isolation resistors and capacitors, andshields after servicing the receiver. Use only manufacturer’s recommended rating for fuses,circuits breakers, etc.High potentials are present when this receiver is operating. Operation of the receiver without therear cover introduces danger for electrical shock. Servicing should not be performed by anyonewho is not thoroughly familiar with the necessary precautionswhen servicing high voltageequipment.Extreme care should be practiced when handling the picture tube. Rough handling may cause itto implode due to atmospheric pressure. (14.7 lbs per sq. in.). Do not nick or scratch the glass orsubject it to any undue pressure. When handling, usesafety goggles and heavy gloves forprotection. Discharge the picture tube by shorting the anode to chassis ground (not to thecabinet or to other mounting hardware). When discharging connect cold ground (i.e. dag groundlead) to the anode with a wellinsulated wire or use a grounding probe.Avoid prolonged exposureat close range to unshielded areas of the picture tube to prevent exposure to x ray radiation.The test picture tube used for servicing the chassis at the bench should incorporate safety glassand magnetic shielding. The safety glass provide shielding for the tube viewing area against xray radiation as well as implosion. The magnetic shieldlimits the x ray radiation around the bell ofthe picture tube in addition to the restricting magnetic effects. When using a picture tube test jigfor service, ensure that the jig is capable of handling 50kV without causing x ray radiation.Before returning a serviced receiver to the owner, the service technician must thoroughly testthe unit to ensure that is completely safe to operate. Do not use a line isolation transformer whentesting.Leakage current cold checkUnplug the A.C. cord and connect a jumper between the two plug prongs.Measure the resistancebetween the jumpered AC plug and expose metallic parts such as screwheads, antennaterminals, control shafts, etc. If the exposed metallic part has a returnpath to the chassis, thereading should be between 240k and 5.2M . If the exposed metallic part does not have areturn path to the chassis, the reading should be infinite.Leakage current hot checkPlug the AC cord directly into the AC outlet. Do not use an isolation transformer during the check.Connect a 1.5k 10 watt resistor in parallel with a 0.15 F capacitor between an exposedmetallic part and ground. Use earth ground, for example a water pipe.Using a DVM with a 1000 ohms/volt sensitivity or higher, measure the AC potential across theresistor.Repeat the procedure and measure the voltage present with all other exposed metallic parts.Verify that any potential does not exceed 0.75 volt RMS. A leakage current tester (such aSimpson model 229, Sencore model PR57 or equivalent) may be used in the above procedure, in2