Panasonic TC-20KL05P Service Manual

Contents

Panasonic TC-20KL05P Service Manual Manual pdf 2 page image

- 2 -TC-20KL05PContentsImportant 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 with the manufacturer’s specified replacementparts to prevent X-ray radiation, shock, fire or other hazards. Do not modify the original design without manufacturer’s permission.!General GuidelinesAn Isolation Transformer should always be used during the servicingof a receiver whose chassis is not isolated from the AC power line.Use a transformer of adequate power rating as this protects thetechnician from accidents resulting in personal injury from electricalshocks. It will also protect the Receiver from being damaged byaccidental shorting that may occur during servicing.When servicing, observe the original lead dress, especially in the highvoltage circuit. Replace all damaged parts (also parts that show signsof overheating.)Always Replace Protective Devices, such as fishpaper, isolationresistors and capacitors, and shields after servicing the Receiver.Use only manufacturer’s recommended rating for fuses, circuitbreakers, etc.High potentials are present when this Receiver is operating. Operationof the Receiver without the rear cover introduces danger from electricalshock. Servicing should not be performed by anyone who is notthoroughly familiar with the necessary precautions when servicinghigh-voltage equipment.Extreme care should be practiced when Handling the Picture Tube.Rough handling may cause it to implode due to atmospheric pressure(14.7 lbs per sq. in). Do not sick or scratch the glass or subject it toany undue pressure. When handling, use safety goggles and heavygloves for protection. Discharge the picture tube by shorting the anodeto chassis ground (not to the cabinet or to other mounting hardware).When discharging, connect cold ground (i.e. dag ground lead) to theanode with a well insulated wire or use a grounding probe.Avoid prolonged exposure at close range to unshielded areas of thepicture tube to prevent exposure to X-ray radiation.The Test Picture Tube used for servicing the chassis at the benchshould incorporate safety glass and magnetic shielding. The safetyglass provides shielding for the tube viewing area against X-ray radiationas well as implosion. The magnetic shield limits X-ray radiation aroundthe bell of the picture tube in addition to restricting magnetic effects.When using a picture tube test jig for service, ensure that the jig iscapable of handling 31kV without causing X-ray radiation.Before returning a serviced receiver to the owner, the servicetechnician must thoroughly test the unit to ensure that is completelysafe to operate. Do not use a line isolation transformer when testing.Warning !It is essential that these critical parts are replacedwith the manufacturer’s specified replacement partsto prevent X-ray radiation, shock, fire or other haz-ards.!ABOUT LEAD FREE SOLDER (PBF) ........................................................ 3SUGGESTED PBF SOLDER .................................................................... 3HOW TO RECOGNIZE THAT PB FREE SOLDER IS USED ......................... 3IC601 - PINOUT ...................................................................................... 5IC601 - PINOUT ....................................................................................... 6IC VOLTAGE TABLES ............................................................................. 6IC601 - BLOCK DIAGRAM ...................................................................... 7GP31 CHASSIS FEATURE SUMMARY .................................................... 8DAC CONTROL FOR GP31 CHASSIS FUNCTIONSANDADJUSTMENTS ......... 9HOW TO RESET THE UNIT (SELF CHECK) ............................................... 9HOW TO ENTER IN THE SERVICE MODE ................................................. 9CHK1 MODE - OPTIONS ......................................................................... 9ADJUSTMENTS ....................................................................................... 10CHK2 MODE - VCJ ADJUSTMENTS ....................................................... 10CHK3 MODE - PINCUSHION ADJUSTMENTS ......................................... 10EEPROM MEMORY MAPS ...................................................................... 11ADJUSTMENTS ....................................................................................... 13CRT P.C.B. .............................................................................................. 18SCHEMATICS DIAGRAMS ....................................................................... 18SHEMATIC DIAGRAM P.C.B. ................................................................... 19MAIN P.C.B. ............................................................................................. 20SIGNAL WAVEFORM .............................................................................. 21EXPLODED VIEW .................................................................................... 25REPLACEMENT MECHANICAL PARTS LIST .......................................... 26REPLACEMENT ELECTRICAL PARTS LIST ............................................ 27