I accidentally changed the display setting on my mac mini to 1080p.  As soon as I did this, it went black.  I wasn't thinking, ... the TV is only 720p.  And so, now I am trying to change the setting back to a lower resolution but all I have to work with is a black screen.  As the computer is starting up, I see the apple screen then it goes black.  I have tried "safe" mode by holding shift but it has gotten me no where.  Anybody have any ideas for me???