Panasonic PT-AX200E LCD Projector - green screen

The LCD panels of your projector are starting to fail. Unfortunately you'll need to have the whole LCD block replaced.

The main board of the projector needs replacement! not worth getting it replaced as it would cost very high! look out for a old working board that would cost lower!

Experience:
There is three LCD (liquid crystal display) in your projector when one LCD faulty he display a line some time flickering line one or two lines. Due to other two LCD is working well so this line is looking transparent. If BLUE LCD faulty than the line color is very light green or yellow.

Second option is this that your projector lamp life is near to end and after 2000 hours projector is very dirty inside and need service.
(service of LCDs and other parts of projector is a very technical job and I don't know you can do it or not)

Three LCD block in the Panasonic projector PT-L735 green,blue and red and two polarizer use with each LCD (as show in picture below) when polarizers faded due to age or any other reason then screen show the color. In your cause the green polarizers faded and need to be replaced

Please adjust the VGA cable properly
Make sure the cable is properly fitted

Have never worked on a panasonic projector before I admit, but you get that effect when the 3 LCD panels inside a Sharp (and I assume all brands) LCD are misalligned. To get total black (LCD Projectors find this rather difficult due to the technology) the red , blue and green lcd pixels must be precisely allignend ( they are adjustable by technician and it's a fiddly job) I reckon the green panel is a touch out and it's peeking out between the red and blue squares.

unless there is a major obstruction, you suspect correctly. also, check the light filter on the blue lcd. that may be fried as well.

could b ballast or powercsupply board

your color calibration may be off. see if you can set the red green and blue settings all to "0" and see if that works. may want to refer to your manual and see how you can do that and also see if there is a auto calibration

Whats the resolution on the Projector?