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Danger  --  C Lin, S Lin, etc. (Convergence)

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Attention all DIY-ers! Convergence warning to those who don’t have the simpler convergence patterns like the 64 point and the usual Mitsubishi quadrant array, and the Zenith/Ampro projector types. These are EASY compared to the older Sony and Pioneer types, which contain hidden land mines. This also includes the TS series of Mits’s, which is mostly quadrant type, but has a few “added features” in its convergence array. 

Some of the worst U.S. Marine language ever heard, I’m certain, has come from the mouths of innocent-minded big screen DIY-ers, who stepped on the land mines called S Lin, C Lin, Mid Lin, Mid Pin, etc. -- all versions of Linearity and Pincushion. 

These innocent-sounding labels gloss over the fact that each of these locations in your convergence circuit completely rebias the entire linearity and pincusion curves used in these particular algorithms in the convergence pattern generator of your big screen.

ALL SUCH LOCATIONS ABSOLUTELY NEED TO BE RECORDED BEFORE ALTERED. This means using a THIN Sharpie pen mark on screwdriver pots, and/or writing down the values you started with, if done in a remote-controlled service menu. You HAVE to know where you started, on each pass, to be able to get these right.

I strongly suggest NOT TOUCHING THEM! EVER! Leave this part of your calibration to a professional—and this eliminates 90% of the warranty and freelance service techs out there, who are repairpeople, and abysmally ignorant of such finer points as this.

This means, if you have a service tech over to do your convergence, it would be a VERY good idea to make sure he doesn’t touch any of these controls. Get him to agree to it, unless he can make you feel comfortable that he knows what he’s doing around these particular parameters/controls.

Even I, as a professional tweaker, cringe whenever I have to remedy a problem involving these parameters; and be forewarned, to do so is NOT covered in the basic calibration package I offer. If you or anybody else has already futzed with them at all -- or even if you simply are not satisfied with the factory settings -- and I am asked to redo them to make your picture better, be prepared to pay extra. Otherwise we leave them as they are and work the rest of the convergence around them. 

Sub Pin and Sub Key are much more predictable, tho they also require special attention, such as redoing the width/height and regular linearity to compensate, on each pass with these parameters. The others are in a league of their own.