NEC PG Series

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      >> Mechanical Setup Procedure 
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RED & BLUE ALIGNMENT

Now with the green crosshair up, turn on the red tube and see where things are. Here is where an important step comes in. To center the crosshair VERTICAL bar, you must move the entire tube/lens assembly (toe-in adjustment). Loosen the 2 brass screws on top of the CRT bracket that lock the tube into one of several preset positions. Remove the “preset” screw and move it to the curved slot right next to it. Now loosen the 2 black screws for that tube as well. DO NOT TOUCH THE GREEN! You will have to carefully and gently wiggle the entire lens/crt assembly right or left to align the center portion of the VERTICAL bar on top of the GREEN. Look at the center for this. Once the vertical bar is aligned, tighten the screws again.

You then use the centering magnets to align the red HORIZONTAL bar to the green. While doing this, everything moves, but don't worry. The goal is to get the dead center to line up. You are also just trying to get the horizontal lines all aligned. You'll correct the vertical lines during the convergence setup. You may need to rotate the red deflection yoke to make it level. Now repeat the focus and astigmatism procedure for the red tube. Take your time. Do not loosen the CRT again.

Once the red is completed, repeat everything with the blue.

NOTE: When you close the deflection board cover and the projector cover, the red static convergence will move. This is normal, and caused by magnetic interference. To fix this, you must compensate for this shift by purposely aligning the red centering rings so that everything moves into place when the cover is closed. It is not hard at all. Try it, and you'll see what you need to do. Do NOT touch the astig magnets anymore!

Ok, once all 3 tubes are done and focused, don't forget to flip the BLUE DEFOCUS switch back to ON. This is done to improve white balance. The blue MUST be slightly out of focus to be bright enough for good grayscale.

At this point you need to reset your background color balance. Turn the brightness to “50” and the
contrast to “75”. Store these values. Now hit KELVIN.

Important Note before continuing:  Do not adjust the Kelvin (color temperature) settings without writing down the original values first in case you make things worse!

While looking into each tube, adjust the “B” or Background, or Black level, whatever you want to call it until the raster for that color JUST vanishes. Do it slowly, go back and forth if needed. I actually set my unit to where I can just barely make out the raster. It's personal Preference, as long as all 3 are the same. Store those settings. You can now adjust the “W” or white sliders using a greyscale pattern or black and white image to achieve best grey to your liking. This is rough, but quite usable without a color analyzer.

Store all settings.

So now you should have properly focused and centered images on your screen. With the static convergence set to ZERO, you should have perfect, or very near perfect convergence in the CENTER of your screen, all without making any electronic corrections!! It is now just a matter of dialing in all the edges using the menu controls.

The Mechanical part is done. Don't forget to store this entry as the default while you are at it. The next time you need to create a new entry, simply select default as your initial data, and you have your proper starting point again. NOW, if your crosshair does not fall into the exact center of your screen, adjust the projector itself up, down, left or right to center it. DO NOT USE ANY MENU'S FOR THIS!!! THAT'S how the alignments originally get screwed up. NOTE: once you complete this procedure you'll need to follow the install manual for completing the electronic convergence setup.

Also, please refer to other articles such as Guy Kuo's "holy focus" document for more advanced techniques, as well as the setup manual for an illustration of the astigmatism procedure and details on the convergence procedure.

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