Panasonic TX-25FG20R Service Manual

4.1.1. +B VoltageItem / preparation1. Operate the TV set.2. Set control as follows :Brightness ........... minimumContrast .............. minimumAdjustment Procedure1. Confirm the DC voltage at the indicated test points, asfollows:TPD 15 : 3.3 ± 0.2VTPD 16 : 141 ± 2VTPD 17 : 8 ± 2VTPD 18 : 1.8 ± 2VTPD 19 : 5 ± 2VTPD 20 : 220 ± 2V4.1.2. RF AGCItem / preparation1. Receive a colour bar signal at an RF level of 69 ±2 dBUwith 75Ω loaded.2. Connect digital multimeter to RF AGC at Tuner.Adjustment Procedure1. Select “RF AGC” indication in CHK2, on Screen byremote control at factory mode.2. Set RF AGC by using remote control Volume (+) orVolume (-) button until voltage AGC at Tuner reaches0.2V at TPD 30 (Tuner point).3. Increase RF signal strength by 2dB, confirm AGC atTuner voltage drop.1. Set Bright and Contrast controls to their maximumpositions.2. Operate the TV set over 60 minutes.3. Full degauss the picture tube by using an externaldegaussing coil. By rotating R-B static convergencemagnet.4. Apply a crosshatch pattern signal and adjust roughly thestatic convergence magnets.5. Apply a green pattern signal.4.1.3. High VoltageItem / preparation1. Receive the crosshatch pattern.2. Set to 0 Beam.Screen VR .......... minimumContrast .............. minimumAdjustment Procedure1. Connect a DC voltage meter to D866 and confirm the+B voltage is 141.0 ± 1.5V.2. Connect a high frequency voltmeter to heater andconfirm that voltage reads 6.3 ± 0.28 (VRMS).3. Normalize the brightness and contrast.4.1.4. NTSC TINT COLOURItem / Preparation1. Connect oscilloscope probe to TPL1 (R OUT) with 10kΩseries resistor.2. Press Main Menu and set system to use AV-NTSC(3.58 MHz)DYNAMIC ................. NormalChannel CLR Set ..... STDAdjustment Procedure1. Adjust Sub-Tint so that No. 2, 3 and 4 becomes levelwaveform is similar to Fig. 3.2. Confirm phase at Tint is changes more than ± 15 by Tintcontrol.3. Confirm that colour level is maximum when colour DACis adjusted to maximum position.Note: Use remote control only when adjusting usermode to Sub-Tint.6. Loosen a clamp screw for the Deflection Yoke and movethe Deflection Yoke as close to the purity magnet aspossible.7. Adjust the purity magnet so that a vertical green field isobtained at the center of the screen.4 Adjustment Procedure4.1. Adjustment Procedure4.2. COLOUR PURITY7TX-25FG20R