Sanyo DS25520 Manual

Also see for DS25520: Owner's manual Owner's manual Owner's manual Service manual Manual

Contents

Sanyo DS25520 Manual Manual pdf 12 page image

— 10 —MAGNET TABSANGLE OF MAGNET TABSSIX-POLEMAGNET TABS FOUR-POLEMAGNET TABSANGLEOF TABSPURITYMAGNETTABS432 1FOCUS GAP(G3-G4)Figure 3. Adjusting MagnetFigure 2. Purity and Convergence MagnetsPURITY ADJUSTMENTS1. When replacing picture tube or deflection yoke, mountdeflection yoke and purity and convergence magnetsassembly properly. See Figure 1. Position the picturetube facing east or west. Demagnetize the picture tubeand receiver using an external degaussing coil. Setreceiver to Service Menu NO. 73 (no vertical sweep)while degaussing.2. Place the yoke on tube neck fully forward against glass.3. Place the CPM on the tube neck aligning the center ofthe purity magnet tabs over center of Focus Gap (G3 & G4).See Figure 2.4. Connect a color-bar generator to the antenna terminal.Switch the generator to a white field. Move yoke back-ward on the neck until a uniform white field is obtained.5. Allow 30 minutes warm up on a blank white field (highintensity grayscale).Note: If white field cannot be obtained check GrayscaleAdjustments on page 8.6. Reset the picture controls to the Auto levels. Select a greenraster, either with the signal generator or by adjusting thebias controls. If a signal generator is used for this step skipto Step 11. If the bias controls will be used go to step 7.7. Adjust Service Menu NO. 15 RB (Red Bias), NO. 16 GB(Green Bias), and NO. 17 BB (Blue Bias) data each to 00.8. Select Service Menu NO. 73 (no vertical sweep).9. Adjust the Screen Control counterclockwise until thehorizontal scan line is no longer visible.10. Select Service Menu NO. 16 GB (Green Bias) andincrease the data to produce a green raster. If retracelines appear reduce screen control slightly.11. Pull yoke back on tube neck to obtain three-color raster(blue, green and red).12. Adjust the angle between the two purity magnet tabs tocenter the vertical green belt in the picture tube. Do notrotate tabs. See Figure 3.13. Slowly slide the deflection yoke forward until a uniformgreen screen is obtained.14. Check the purity of the red and blue screens for unifor-mity. Turn off other colors to check (use bias controls oruse generator). If necessary, readjust the yoke positionuntil all screens are pure.15. If bias controls and screen control were used to set puri-ty reset Grayscale and Bright Level. Refer to GrayscaleAdjustment on page 6 and Brightness Level Adustmenton page 7.16. Confirm that the yoke is not tilted. Tighten the yokemounting screw. Adjust convergence next.RUBBERWEDGEDEFLECTION YOKEDEFLECTION YOKEMOUNTING SCREWFigure 1. Deflection Yoke MovementPURITY AND CONVERGENCE ADJUSTMENTSCAUTION: The Purity and Convergence adjustments have been made at the factory. Readjustments should be madeonly after the picture tube or deflection yoke is replaced. Follow the steps below for necessary readjustments.