SOLUTION (at least for me!)
1) Go ahead and turn off the MacBook Pro and disconnect everything from all ports.
2) Then plug in your 85W MagSafe Power Adapter that came with your computer.
3) HOLD Control + Option + Shift and afterwards, press the power button ONCE. (Nothing should turn on) --> This will reset some console/management drivers which may have glitched during a software update.
4) Turn on the computer (normally, without pressing anything)
5) After it is fully booted up, plug in your Minidisplay Port --> DVI --> HDMI cord and you should be up and going with your second monitor/TV/etc.
Hope this works for you like it did for me.
1) Go ahead and turn off the MacBook Pro and disconnect everything from all ports.
2) Then plug in your 85W MagSafe Power Adapter that came with your computer.
3) HOLD Control + Option + Shift and afterwards, press the power button ONCE. (Nothing should turn on) --> This will reset some console/management drivers which may have glitched during a software update.
4) Turn on the computer (normally, without pressing anything)
5) After it is fully booted up, plug in your Minidisplay Port --> DVI --> HDMI cord and you should be up and going with your second monitor/TV/etc.
Hope this works for you like it did for me.
