Panasonic TC-14A12P Service Manual

Contents

Panasonic TC-14A12P Service Manual Manual pdf 21 page image

- 21 -TC-14A12P / TC-20B12Service Adjustments and CalibrationsTEST EQUIPMENTTo do all of these electrical adjustments, the following equipmentis required:• Dual-Trace OscilloscopeVoltage Range: 0.001 V to 50 V/Div.Frequency Range: DC to 50 MHzProbes: 10:1, 1:1• NTSC Video Pattern Generator• DVM (Digital Volt Meter)• MTS/SAP Signal Generator• (TV Multi-Channel Sound Modulator (U.S.A.))• Plastic Tip Driver and Non-Metal Driver• Isolation Transformer (Variable)• Degaussing Coil• White Pattern Generator• Audio GeneratorAGC RF CALIBRATION1. PREPARATION:1.1. Receive a color bar pattern and assure a RF input signal of75Ω opened, channel 13 (211.25 MHz).1.2. Connect the digital multimeter in TPA 15.2. CALIBRATION:2.1. Select the option “RF AGC” in the “CHK2” service mode.2.2. Adjust RF AGC to 2.2±0.1V in TPA20.3.3. Increase the input level by +2 dB and confirm that the voltagedecrease.Tuner ENV56D75G3R TEDH9-301ALevel 69dB mV 69dB mVVIF DETECTOR OUTPUT LEVEL CONFIRMATION1. CALIBRATION:1.1. Install the chassis in the VIF calibration JIG and receive acolor bar pattern with 63 dBU (75Ω opened).1.2. Connect the oscilloscope to TPA33.1.3. Confirm that the video output signal is within a range of 1.05± 0.15 Vp-p in TPA33.BUZZ (SOUND CIRCUIT)1. PREPARATION:1.1. Connect the oscilloscope with a 7kHz filter between TPA41and ground or between the speaker’s terminals1.2. Adjust the sound volume to the maximum.1.3. Set “TONE” to “NORMAL” and “AVL” turned off.2. CONFIRMATION:2.1. Receive a color bar pattern channel 2, with local frequencyadjusted and the AFC turned on (Channel with sound bearer andwithout modulation).2.2. Assure that the width in the buzzing waveform is smaller than500 m Vp-p.ANODE AND HEATER VOLTAGE CONFIRMATION1. PREPARATION:1.1. Receive a crosshatch pattern.2.2. Adjust the bunch current in zero. (0 beam)3.3. Adjust “SCREEN VR” and “CONTRAST” to minimum.2. CONFIRMATION:2.1. Connect a voltage meter between TPA12 and ground. Confirmthat the voltage +B is within a range of 140.5V± 1.5V2.2. Connect a high frequency voltage meter (VRMS.) among theheater, and confirm that the reads tension is within a range of 6.3± 0.24 (VRMS)2.3. Connect the high voltage meter in the CRT anode pin, andconfirm that the high voltage is within a range of [A]:• TC-14A12P [A]=24.5 +0.7kV _1.5kV• TC-20B12 [A]=26.5 +0.7kV _1.5kVPAL COLOR OUTPUT SIGNAL ADJUSTMENT1. PREPARATION:1.1. Receive a color bar pattern and adjust the local frequency.1.2. Adjust “IMAGE” to DYNAMIC NORMAL, “CONTRAST” to 63and “SUB-CONTRAST” to 21.1.3. Adjust the “COLOR FOR CHANNEL” level to NORMAL.1.4. Set the CHK2 service mode option, press “5” on the remotecontrol unit and confirm that OSD becomes blue (AKB turned off).1.5. Connect a short circuit jumper between TPA10 and TPA20.1.6. Adjust [A] for 2.3 ± 0.2V through the BRIGHT control variationin the test point TPL2.1.7. Fix G-DRIVE GAIN, R-DRIVE GAIN and B-DRIVE GAIN datain 1FH or 31 DAC.2. CALIBRATION:2.1. Connect the oscilloscope in TPL2 (G-OUT) with a 10KΩresistor and adjust “CONTRAST”, so that the waveform in [B] it isof 2.6±0.1V according to fig. 1.2. Adjust “SUB-COLOR” to obtain 2,45±0.1V in [D] according tofig. 1.3. Connect the oscilloscope in TPL1 (R-OUT) a 10KΩ resistor inand confirm that the waveform in [C] it is of 2.45±0.1V accordingto fig. 2.4. Remove the jumper between TPA10 and TPA20, press “5” andconfirm that OSD becomes white (AKB turned on).A=2.3±0.2Vp-pB DFig. 1A=2.3±0.2Vp-pCFig. 2