Hi there, I was sure this problem was tackled since it first appeared, but apparently not. I plugged in a MBP, late 2011 issue, to a 1360x768 TV through HDMI connection, and got a translucent blue screen both on the TV and MBP. Translucent because on sticking my nose to the screen, I could indeed see the windows "behind" it. From one try to the other, sometimes I got "Not supported" displayed on the TV, as if I selected the wrong resolution. During this time, nothing showed in the Console. I also tested the VGA connection on the same TV, but it failed to be detected, however. On connecting a MacBook to the MBP through screen sharing, I could see plugging in the TV was correctly detected, and the correct resolution sent. I could even slide the "overscan" slider and see the blue rectangle changing in size accordingly. If that's interesting, when I unplugged the TV from the MBP, sometimes it kept the "Disposition" tab in the Monitors pane, as if more than one monitor was plugged in. I already tried doing a deep clean on startup with AppleJack, to no avail. Then I reversed the roles: the MacBook (late 2009) was plugged in the TV, MBP controlled its screen, and the exact same signes appeared, although they were running different OS X versions (MBP on Snow Leopard, MB on Yosemite beta) and had, obviously, different adapters. FWIW the TV itself does work, as I could play a movie without a problem with a Raspberry Pi. As there are no messages in the Console, what could be the problem, then?