Panasonic TC-20KL05P Service Manual

Contents

Panasonic TC-20KL05P Service Manual Manual pdf 16 page image

- 16 -TC-20KL05PADJUSTMENTSITEM / PREPARATION PROCEDURE11- WHITE QUALITY CALIBRATIONPREPARATION:1. Adjust the HELMHOLTZ device to local magnetic field. Ho-rizontal: 0 ± 0.003 x 10-4 T2. Receive a white purity pattern.3. Adjust CONTRAST and BRIGHT controls to maximum.4. Previously adjust the CONVERGENCE.5. Fully degauss the CRT by using an external degaussingcoil.CALIBRATION:1. Adjust the magnetic field in 0.4x10-4T (400 mG), andcheck the white quality with the CRT turned to EAST andto WEST.2. Receive a red pattern, adjust the COLOR control tomaximum and confirm the purity adjustment.3. If purity error is found at the CRT corners, apply magnetictapes to correct it, fully degauss the CRT again and repeatthe steps 1 and 2. Don't use this magnetic tapes on theinternal side of the yoke.4. When magnetic tapes be used, fully degauss the face ofCRT (in a horizontal magnetic field = 0 ± 0.03x10-4T),and repeat the items 1 and 2.5. Adjust the control of COLOR to MINIMUM, and repeatingthe item 1.12- CONVERGENCE CALIBRATION1. Adjust the HELMHOLTZ device to local magnetic field.2. Receive a crosshatch pattern.3. Adjust IMAGE menu to DINÂMIC NORMAL and the DACBRIGHT control for the crosshatch pattern to be gray.4. Remove the DY wedges and slightly tilt the deflectionyoke to the vertically and horizontally to obtain the goodoverall convergence.5. If purity error is found, repeat “Color Purity” adjustmentCALIBRATIONStatic convergence calibrationl) Assure that the magnets are positioned according toillustration 1.ll) Adjust the 4 poles magnets to align the R and BCENTRAL DOTS and adjust the 6 poles magnets toalign both DOTS with G.lll) After adjustment above, assure that the magnets aresealed, through the application of white glue.Note:The electron beams are moved rotationally when thestatic convergence magnets are rotated.The reduction of rotational beams differ depending ofthe two magnets angle. Therefore, it is necessary torepeat the magnets calibrations sometimes, untilobtaining a good alignment.13- CRT CUT OFF CALIBRATION1. Supply a WINDOWS signal.2. Position DACs with the data below:BRT —> 50HS-BRT —> 31HRGB CONTRAST —> 02DACSUB-CONTRAST —> 21HR,G,B DRIVE —> 31HR,G CUT —> 31HCALIBRATION:1. Press “5” (AKB OFF) and confirm that OSD becomesblue.2. Connect the oscilloscope in TPL5 and adjust BRT toobtain 130V as in the Fig. 1 below.3. Adjust the SCREEN to obtain a horizontal fine line in thescreen center.4. Press “5” (AKB ON) and confirm that OSD becomeswhite.4 poles magnets (R-B)6 poles magnets (R-G-B)Fig. 1