Sanyo C25ZG45 Service Manual

Also see for C25ZG45: Instruction manual

PURITY AND CONVERGENCE ADJUSTMENT‘%9# ICAUTION: The Convergence and Purity adjustments have been made at the factory. Readjustment should bemade only after picture tube or deflection yoke replacement, following the steps below:PURITY ADJUSTMENT1. Demagnetize the picture tube and receiver using an externaldegaussing coil. When replacing picture tube or deflectionyoke, mount deflection yoke and purity - convergencemagnets assembly properly, see figures 1 and 4.2.Turn Red and Blue guns off and provide only Green raster,Rotate Screen control to fully counterclockwise. Rotate Redand Blue Bias controls fully counterclockwise. Slowly rotateGreen Bias control clockwise to produce Green raster.3. Loosen the screw holding the Deflection Yoke and removethe 3 Rubber Wedges, and slide the Deflection Yoke fullyfrontward.4. Rotate and spread the Tabs of the two Purity Magnets tocenter the vertical green belt in the picture screen. The PurityMagnets are also adjusted to obtain vertical centering of theraster.5. Slowly slide the Deflection Yoke backward until a uniformgreen screen is obtained.6. Check the purity of the red and blue screens for uniformity,turn off other colours to check this (use bias controls).Readjust the yoke position if necessary until all screens arepure.7. Adjust each Bias control and screen control to obtain white8. Tighten the mounting screw of the Deflectionyoke. AdjustConvergence next.CENTER CONVERGENCE ADJUSTMENT1.Use a dot crosshatch pattern signal.2. Turn Red and Blue guns on and turn off Green gun. Adjustthe angle between the Tabs of the Four Pole Magnet 1and2,and superimpose the Red and Blue vertical lines in thecenter area of the picture screen. Refer to figure 2.3. Keeping the mutual angle of the Tabs of the Four PoleMagnet turn them together to superimpose the Blue and Redhorizontal lines in the center area of the picture screen. Referto figure 2.4. Turn Green gun on and adjust Six Pole Magnet 3 and 4s thatthe Green line superimposed on the Red/Blue lines,This is the same procedure used in steps 2 and 3.Refer to figure 3.OUTER AREA CONVERGENCE ADJUSTMENTSlightly loosen the screw holding the Deflection Yoke. Adjustthe Deflection Yoke to converge the detail in the outer area (leftside and right side) of the picture screen by orbital movement ofthe front of the Yoke, then secure the Deflection Yoke inraster. Refer to Gray Scale Adjustment. If part of the picture appropriate position by putting the wedges as illustrated.screen is coloured, adjust the Deflection Yoke position Tighten screw holding the Deflection Yoke.forward or backward slightly.DEFLECTION YOKEFOUR- POLEMAGNET TABSrxSIX- POLEMAGNET TABSFigure- 1. PURITY AND CONVERGENCE MAGNETS~Figure- 4. ADJUSTMENT DEFLECTION YOKEAdjust tabs angle to superimposeblue and red vertical lineJ Adjust tabs together toRED+superimpose red and\--- :;__ L/ blue horizontal lineBLUE IAdjust tabs angle to superimposered/blue and green vertical line7-t-rf -BLUE/RED IIFigure-2 BLUE AND RED LINE MOVEMENT I Figure-3 BLUE/RED AND GREEN LINE MOVEMENT-11–