If everything works find on TV number 2, maybe TV number 1 is broken? Two easy testing suggestions:
1) Are you sure that the correct input is selected? I've seen people with the wrong input selected and then - poof! No picture.
2) If the Orion has more than one HDMI input, try using one of the other ones.
It is possible for the HDMI video inputs to break. Can be caused by voltage surges. If it were a first or second tier brand you might be able to get a replacement HDMI board. You would have to contact Orion to see if it is worth doing.