Panasonic TC-20B10P Service Manual

Panasonic TC-20B10P Service Manual Manual pdf 2 page image

- 2 -General GuidelinesAn Isolation Transformer should always be used during the servicing of areceiver whose chassis is not isolated from the AC power line. Use atransformer of adequate power rating as this protects the technician fromaccidents resulting in personal injury from electrical shocks. It will alsoprotect the Receiver from being damaged by accidental shorting that mayoccur during servicing.When servicing, observe the original lead dress, especially in the highvoltage circuit. Replace all damaged parts (also parts that show signs ofoverheating.)Always Replace Protective Devices, such as fishpaper, isolation resistorsand capacitors, and shields after servicing the Receiver. Use onlymanufacturerís recommended rating for fuses, circuit breakers, etc.High potentials are present when this Receiver is operating. Operation ofthe Receiver without the rear cover introduces danger from electricalshock. Servicing should not be performed by anyone who is not thoroughlyfamiliar with the necessary precautions when servicing high-voltageequipment.Extreme care should be practiced when Handling the Picture Tube. Roughhandling may cause it to implode due to atmospheric pressure (14.7 lbsper sq. in). Do not sick or scratch the glass or subject it to any unduepressure. When handling, use safety goggles and heavy gloves forprotection. Discharge the picture tube by shorting the anode to chassisground (not to the cabinet or to other mounting hardware). Whendischarging, connect cold ground (i.e. dag ground lead) to the anodewith a well insulated wire or use a grounding probe.Avoid prolonged exposure at close range to unshielded areas of the picturetube to prevent exposure to X-ray radiation.The Test Picture Tube used for servicing the chassis at the bench shouldincorporate safety glass and magnetic shielding. The safety glass providesshieldinf for the tube viewing area against X-ray radiation as well asimplosion. The magnetic shield limits X-ray radiation around the bell ofthe picture tube in addition to restricting magnetic effects. When using apicture tube test jig for service, ensure that the jig is capable of handling31kV without causing X-ray radiation.Before returning a serviced receiver to the owner, the service technicianmust thoroughly test the unit to ensure that is completely safe to operatore.Do not use a line isolation transformer when testing.Important Safety NoticeSpecial components are used in this television set which are important for safety. These parts are identified on the schematicdiagram by the symbol . It is essential that these critical parts are replaced whit the manufacturerís specified replacementparts to prevent X-ray radiation, shock, fire or other hazards. Do not modify the original design whitout manufacturerís permission.WARNING !!Esquema ElÈtrico do chassi MX5Y ................. (em anexo)Conserve-o sempre junto deste manual.TABLE OF CONTENTSOPERATION GUIDE ............................................................................. 03SERVICE ADJUSTMENTS AND CALIBRATIONSHOW TO OPERATE THE DAC CONTROLS ..................................... 06HOW TO ENTER THE SERVICEMAN MODE ..................................... 06HOW TO EXIT THE SERVICEMAN MODE ......................................... 06DAC DIRECT TABLE ............................................................................ 07MEMORY - DIRECT ACCESS METHOD ............................................. 07EEPROM - MEMORY MAP .................................................................. 07ELECTRICAL INSPECTION .................................................................. 07INSPECTION OF THE DEFLECTION CIRCUITS ................................ 07CUT OFF - PRE ADJUSTMENTS ........................................................ 08CALIBRATION OF VIDEO IF ................................................................ 08AFT ADJUSTMENTS ............................................................................. 09AGC-RF ADJUSTMENTS ...................................................................... 09NOISE LEVEL ADJUSTMENTS ............................................................ 09VIDEO OUT ADJUSTMENTS ............................................................... 10SUB-CONTRAST ADJUSTMENTS ....................................................... 10COLOUR SATURATION ADJUSTMENTS .......................................... 10SHARPNESS ADJUSTMENTS ............................................................. 10SHUT DOWN SYSTEM COFIRMATION .............................................. 10HORIZONTAL WIDTH AND CENTERING ADJUSTMENTS .............. 11VERTICAL HEIGHT AND CENTERING ADJUSTMENTS ................... 11WHITE BALANCE PRE ADJUSTMENTS ........................................... 11CRT CUT OFF ADJUSTMENTS ........................................................... 11FOCUS ADJUSTMENTS ..................................................................... 12FRONT PANEL CHECKING ................................................................. 12AV IN TERMINALS CHECKING ........................................................... 12AUTOMATIC AND MANUAL MEMORIZATION .................................... 13TUNE CHECKING ................................................................................. 13AUDIO CHECKING ................................................................................ 13PURITY AND CONVERGENCE ADJUSTMENTS .............................. 14SCHEMATICS DIAGRAMS ................................................................... 15IC601 BLOCK DIAGRAM / PINS AND FUNCTIONS ........................... 16WAVE FORMS ...................................................................................... 17CABINET PARTS LOCATION ............................................................... 19CABINET REPLACEMENT PARTS LIST ............................................. 20ELECTRICAL REPLACEMENT PARTS LIST ...................................... 21Warning !It is essential that these critical parts are replacedwith the manufacturerís specified replacement partsto prevent X-ray radiation, shock, fire or otherhazards.HOW TO OPEN THE CABINETScrewScrew