HDMI out - how the hell does this work

[knives of ice]

ok, what am i missing here. i come from the touch pro and touch pro2 where you'd plug in the tv out cable and notification of it being plugged in would automatically come up. today i get my hdmi cable for my evo plug it in and hook it up to the tv and i got nothing. no picture on the tv, nothing. try youtube, try the gallery and nothing. i try this on 3 hdtv's with hdmi and get the same on all 3. one time briefly i saw the HDMI icon come up in the notifications area then it soon went away.

what is the normal notification when you plug in the hdmi on the evo?