arduino IDE isn't able to load skethes to my arduino mega board
I'm Really sorry I wasted your time, I finally discovered it was a software bug, not hardware. trying the board on a different computer worked fine. trying a different board on my laptop made the same bug. When I uninstalled the IDE and re-installed it after that the problem remained. Finally I solved it deleting the preferences file, the hardware folder and the libraries folder (those which are on the sketchbook folder). Thank you anyway.