Panasonic CT-27D10B Service Manual

Also see for CT27D10DB - 27" COLOR TV: User guide

Panasonic CT-27D10B Service Manual Manual pdf 11 page image

- 11 -Purity and Convergence ProcedureAdjustment is necessary only if the CRT or thedeflection yoke is replaced or if the setting wasdisturbed. The complete procedure consists of:1. Vertical Raster Shift Adjustment. (Only for Modelswith Purity/Convergence Assembly with 4 Pairsof Rings).2. Initial static convergence.3. Setting the purity.4. Final static convergence.When the CRT or the Yoke is ReplacedPlace the yoke on the CRT neck (do not tightenthe clamp).For a 2-piece assembly (see Fig. 5):Position purity/convergence assembly as shown andtighten clamp snugly. Remove the hot-melt glue sealon assembly and position like tabs of purity devicetogether at 12 o’clock to reduce its magnetic fieldeffect.For models using 4 pairs of rings, place the verticalraster shift tabs at 3 o’clock (90o from the purity andconvergence tabs, see Fig. 6 and Fig. 7)For a 1-piece assembly (see Fig. 8):Position like tabs of purity devices together at 12o’clock to reduce any magnetic field effect. (For betterresults, note part number and look for specifications atService Center)For either assemblies:Turn the Receiver ON. Operate the Receiver for 60minutes using the first Purity Check field (white screen)to stabilize the CRT.Fully degauss the Receiver by using an externaldegaussing coil.Slide the deflection yoke back and forth on the neck ofthe CRT until it produces a near white, uniform raster.Vertical Raster Shift Adjustment (Only forModels with Purity/Convergence Assembly with 4Pairs of Rings).Apply a green pattern with a horizontal line, adjust theDeflection Yoke so that has no tilt, then secure it.Adjust center line of the pattern with the mechanicalcenter of the CRT, this center is determined by twomarks at the side edges of the screen. To adjust theline, once the vertical raster shift tabs are place at 3o’clock to reduce its magnetic field effect (see Fig. 6and Fig. 7) open the tabs the same angle from thecenter, until the center line of the pattern becomes astraight line, centered with the marks of the CRT. (seeFig. 9)G3 G4Purity Rings CenteredOver G3/G4 GapR&B Convergence RingsR&B&G Convergence RingsFigure 5. Positioning of Purity/Convergence Assembly(2-piece assembly)G3 G4Purity Rings CenteredOver G3/G4 GapR&B Convergence RingsR&B&G Convergence RingsVertical Raster Shift RingFigure 6. Positioning of Purity/Convergence Assembly(4 Pairs of Rings)90 oPurity RingsVertical RasterR&B Convergence RingsR&B&G Convergence RingsFigure 7. Positioning of Purity/Convergence Assembly(4 Pairs of Rings)Shift RingsFigure 8. Positioning of Purity/ConvergenceAssembly (1-piece assembly)Vertical Raster Shift tabsOpen thesame anglefrom centerFigure 9. Vertical Raster Shift Adjustment(4 pairs of rings assembly)Center Marksfrom patternCenter lineMechanical