NotTaR of Television Sets : Removing and replacing the deflection yo..  
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Removing and replacing the deflection yoke

Should you need to remove the deflection yoke on a color CRT, some basic considerations are advised both to minimize the needed purity and convergence adjustments after replacement as well as to prevent an unfortunate accident.

The position and orientation of the yoke (including pitch and yaw) and magnet assembly (purity and static convergence rings, if used) are critical. Use paint or White-Out(tm) to put a stripe across all of the magnet rings so you will know their exact positions should they accidentally shift later. If there are rubber wedges between the yoke and the funnel of the tube, assure that they are secure. Tape them to be doubly sure as adhesive on old tape dries up with age and heat and becomes useless. This will avoid the need for unecessary dynamic convergence adjustments after reassembly.

The neck is the most fragile part of the CRT so do not apply any serious side-ways force and take care not to bend any of the pins when removing and replacing the CRT socket.

The yoke and purity/static convergence assemblies will be clamped and possibly glued as well. However, the adhesive will probably be easily accessible - big globs of stuff like hot melt glue and/or RTV silicone. Carefully free the adhesive from the glass neck of the CRT. Loosen the clamps and gently wiggle the magnets and yoke off the neck. They may appear stuck from age and heat but should yield with gently persuasion.

Once the yoke is replaced, some fine adjustments of the picture rotation, purity, and static and dynamic convergence may be needed but hopefully with your most excellent diagrams, these will be minimal.

Similar comments apply for monochrome CRTs but there are far fewer issues as the yoke is positioned firmly against the funnel of the CRT and rotation and centering are usually the only adjustments. However, there may be magnets located on swivels or glued to strategic locations on the CRT envelope to correct for geometric distortion.

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