Similar issue here. Haven't used the 360 for a few weeks, went to play today and no signal. Tested cables and and ports on TV and they all work fine (used HDMI from cable box to test). So something is going on with the 360 where the HDMI port just decided to take a leave of absence.

No red rings of death on the 360, it runs and lights are green. Guess I need to find the RCA cables and see if it puts out a signal that way.

Anyone else have any insight/experience with 360 Elite HDMI port just up and quitting with no warning?