Turn on the breakers all four.

We have a key in my plastic drawer bin next to my desk

Tens = the 10 digit # IE 20 or 30. If you are trying to move grid #7 then leave the "Tens" at 0

Projection Screen is #9 

put the Tens dial on 0

Units dial on 9 

then push the Green and Yellow buttons to move the screen up and down

Press and hold the yellow button to move the grid up and down

Green button moves the grid up.

Put knob back to "0" when finished moving the grid.

Turn off the breakers when finished moving the grid.

Note that when you raise and lower the projection screen you will have to adjust the lens

Click on Advanced

click on Projector Lens Control

Then you can adjust the lens so that the image is centered on the screen