The problem with focusing in PA70G, formed by assembly at the factory.
Looking at the lens mount are 3 screws in the Triangle!, The two screws on the left and one on the right.
Upper screw on the left, has a limiting displacement of the pin while turning the lens, the same is to screw on the right. May these two screws thicker plastic distance from the rear.
bottom left screw has a smaller distance and allows small adjustments.
By mounting the lens screw it screw screwdriver, Upper left and right in the middle.
This is to assure proper sharpness diagonally, the image on the screen is reversed, ie the sharpness we have in the lower left corner, and the upper-right corner,
Now screw it screw bottom left, doing the electric screwdriver, screw it all the way.
So the distance is less than the first two screws, support the lens, and the bottom left it skews to the left, down.
as a result we have less distance from the surface of the mirrors, and the sharpness is obtained faster, and in the opposite corner is not sharp, turning the control knob causes the sharpness moves in the direction of the upper left corner but the range ends.
in most cases a small correction may simply removing the lower left screw. the knob is at maximum focus.
I either need to tighten, because she could not be tightened.
That's the first thing you should check for me at the end of the range Focus 100 "is insufficient, and that is why I deleted the plastic on donations to Offer up the entire lens closer to the mirror and get the opportunity, adjusting sharpness beyond the 100" but it is difficult positioning of the lens in the optical axis.
I think that if they were 4 and not 3 screws that were better, but if LG saves on one screw projector at this price! it already is funny