I just finished installing the Ramps board with the graphic lcd. Everything seems to work.
When I select Home, the printer homes fine and I do a manual bed level. When I select print, the printer will home and then goto z max and then start the printing process but the nozzle is 2mm away from the bed.
Why does it go to Z-max? Is it a Delta printer? Is it in your slicers start code?
When the nozzle is above the bed, when it should be at 1st-layer height, you have to adjust the probe offset.
What distance does the nozzle have, when you home the printer?