I have a galaxy nexus, and a pico-projector which I connect to my phone with a MHL cable (micro usb -> hdmi). It used to "just work" when I was on ice-cream sandwich. You'd plug in the cable, and the phone would automatically rotate to landscape and mirror your screen onto the projector, nice!
Recently an over-the-air upgrade to Android version 4.1.2 jellybean installed, and it's b0rked that feature. Now when I plug in the device, it jerks around looking like it's trying to do its thing, and the projector kind of flicks on and off, and then it gives up. The upgrade didn't seem to break anything else. I know the projector is OK because it still works normally with my laptop.
How can I troubleshoot that feature and try to get my HDMI out back? I really miss it.