Panasonic TC-20KL04A Service Manual

Panasonic TC-20KL04A Service Manual Manual pdf 2 page image

- 2 -TC-20KL04A / TC-20KL04P / TC-29KL04A / TC-29KL04PGeneral GuidelinesAn Isolation Transformer should always be used during the servicingof a receiver whose chassis is not isolated from the AC power line. Usea transformer of adequate power rating as this protects the technicianfrom accidents resulting in personal injury from electrical shocks. It willalso protect the Receiver from being damaged by accidental shortingthat 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. Useonly manufacturer’s recommended rating for fuses, circuit breakers,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 servicing high-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 to anyundue pressure. When handling, use safety goggles and heavy glovesfor protection. Discharge the picture tube by shorting the anode tochassis 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 service technicianmust thoroughly test the unit to ensure that is completely safe to operate.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 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.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.ContentsOPERATING INSTRUCTIONS ................................................................ 4IC601 - PINOUT ................................................................................... 5IC VOLTAGE TABLES .......................................................................... 6IC601 - BLOCK DIAGRAM ................................................................... 7GP3 CHASSI FEATURE SUMMARY ..................................................... 8THE DAC CONTROL FUNCTIONS FOR THE GP3 CHASSIS ................... 9SERVICE MODE:HOW TO ENTER IN THE SERVICE MODE .............................................. 9TO EXIT SERVICE MODE AND RETURN TO NORMAL MODE ................. 9ADJUSTMENTS:CHK1, CHK2, CHK3 and CHK4 ADJUSTMENTS OPTIONS ............... 9, 10TEST AND MEASUREMENT EQUIPMENTS REQUIRED ......................... 111- VIF DETECTOR OUTPUT LEVEL CONFIRMATION ......................... 123- BUZZING CONFIRMATION (AUDIO CIRCUIT) ................................ 124- ANODE AND HEATER VOLTAGE CONFIRMATION ........................ 125- PAL COLOR OUTPUT LEVEL ADJUSTMENT ................................ 136- NTSC SUB-TINT CALIBRATION ..................................................... 137- PROTECTION CIRCUIT (SHUTDOWN) OPERATION) ...................... 138- SUB-BRIGHTNESS AND SUB-CONTRAST CALIBRATION ............ 149- FOCUS CALIBRATION ................................................................... 1410- COLOR PURITY ADJUSTMENT ...................................................... 1311- WHITE QUALITY CALIBRATION .................................................... 1412- CONVERGENCE CALIBRATION ..................................................... 1414- CRT CUT OFF CALIBRATION ....................................................... 1515- VERTICAL DEFLECTION CALIBRATION ........................................ 1616- WITHE BALANCE CALIBRATION ................................................... 16EEPROM MEMORY MAPS ................................................................... 17SCHEMATICS DIAGRAMS:CRT PCB SCHEMATIC DIAGRAM ........................................................ 19“G” PCB SCHEMATICS DIAGRAMS .................................................... 20“R” PCB SCHEMATICS DIAGRAMS .................................................... 21“Z” PCB SCHEMATICS DIAGRAMS ..................................................... 22MAIN PCB SCHEMATIC DIAGRAM ...................................................... 23MAIN PCB LAYOUT ............................................................................ 24SIGNAL WAVEFORMS ........................................................................ 25EXPLODED VIEW ................................................................................. 29PARTS LISTS:REPLACEMENT MECHANICAL PARTS LIST ........................................ 30REPLACEMENT ELECTRICAL PARTS LIST .......................................... 31!!