Panasonic CT-25G6E Service Manual

Also see for CT27G6DE - 27" COLOR TV: Operating instructions Service manual

Panasonic CT-25G6E Service Manual Manual pdf 12 page image

- 12 -Purity AdjustmentWhen the Receiver is in the Service Mode for makingelectronic adjustments, press the Recall button on theRemote Control to enter Purity Check. (See theService Adjustments Electronic Controls procedure).Operate the Receiver for 60 minutes using the firstPurity Check field (white screen) to stabilize the CRT.Fully degauss the Receiver by using an externaldegaussing coil.Press the Recall button on the Remote Control againuntil the Purity Check (green screen) appears.For a 2-piece assembly (see Fig. 5):Loosen the deflection yoke clamp screw and move thedeflection yoke back as close to the purity magnet aspossible.Adjust the Purity rings to set the vertical green rasterprecisely at the center of the screen (see Fig. 10).Slowly move the deflection yoke forward until the bestoverall green screen is displayed.For a 1-piece assembly (see Fig. 8):Slowly move the deflection yoke and purity ringsassembly toward the CRT board and adjust the puritymagnet rings to set vertical green raster at center ofscreen (see Fig. 10).Gradually move the deflection yoke & purity ringsforward and adjust for best overall green screen.Continue from here for either assemblies:Tighten the deflection yoke clamp screw.Press the Recall button on the Remote Control againuntil the purity check (blue screen) and (red screen)appear and observe that good purity is obtained oneach respective field.Press the Recall button on the Remote Control againuntil Purity check (white screen) appears. Observe thescreen for uniform white. If purity has not beenachieved, repeat the above procedure.Final Convergence Procedure (see Fig. 11through Fig. 13):Note: Vertical size and focus adjustments must becompleted prior to performing the convergenceadjustment. Connect a dot pattern generator tothe Receiver. The Brightness level should notbe higher than necessary to obtain aclear pattern.Converge the red and the blue dots at the center of thescreen by rotating the R & B pole Static ConvergenceMagnets.Align The converged red/blue dots with the green dotsat the center of the screen by rotating the R & B & Gpole Static Convergence Magnets. Melt wax withsoldering iron to reseal the magnets.Slightly tilt vertically and horizontally (do not rotate) thedeflection yoke to obtain a good overall convergence.If convergence is not reached at the edges, insertpermalloy (see following section) from the DY cornersto achieve proper convergence. Recheck for purity andreadjust if necessary.After vertical adjustment of the yoke, insert wedge at 11o’clock position, then make the horizontal tiltadjustment.Secure the deflection yoke by inserting two sidewedges at 3 and 7 o’clock positions.Apply adhesive between tab (thin portion) of wedgeand CRT and place tape over the tab to secure to theCRT.PermalloyConvergenceCorrectorStrip(PartNo. 0FMK014ZZ)This strip is used in some sets to match the yoke andCRT for optimum convergence. If the yoke or CRT isreplaced, the strip may not be required.First converge the set without the strip and observe thecorners.If correction is needed:1. Place strip between CRT and yoke, in quadrantneeding correction. Slowly move it around fordesired results.2. Press adhesive tightly to the CRT and securewith tape.Figure 10. Green Raster Adjustment