Mac Mini Reverting to 720p from 1080p

Hello Mark,

Seems that the Monitor must be on to communicate to the Mac that it's 1080p, I suspect that it defaults to 720p if the correct info isn't sent from the Monitor/Reciever.

Pins 15 and 16 are dedicated to the DDC (Display Data Channel), used for communicating EDID (Extended Display Identification Channel) information between devices.

http://www.hdmi.org/installers/insidehdmicable.aspx

Seems that the Monitor must be on to communicate to the Mac that it's 1080p, I suspect that it defaults to 720p if the correct info isn't sent from the Monitor/Reciever.

I've got this problem too, it's driving me bananas.

Reverting to 720p or some other random screen resolution makes no clear sense here. There's no guarantee that your connected HDMI device will actually support that resolution either - making this decision for the user is really peculiar.

I'd get it if the behaviour was for OS X to say, "Oh hey, look, a new display, let's resize!" and do that with each event, but it just doesn't. Connecting HDMI devices via receiver is not some kind of magical weird configuration, it's super-common.

I'd kind of rate this as a massive Apple fail, except that when I posted this question on the Plex forums (http://forums.plexapp.com/index.php/topic/45036-resolutions-and-receivers/) someone's suggested that a re-install fixed it. That speaks to me that there is some kind of setting that controls this behaviour, but unlocking that would be the key.

Why - really - why would you make an HDMI device with a native HDMI port that didn't play well with receivers for HDMI switching??

That makes perfect sense. I had the problem too.

Throw an AV receiver into the mix and you have another thing that can go wrong (receiver not powered) when transporting the display properties back to the mac.

I had this problem and now I always make sure that the TV is switched on before the receiver and then mac.

No problems since I have used this procedure.

See my reply to the same issue in this thread. You need the same solution.

https://discussions.apple.com/thread/3041540?tstart=0

I think you're on it John, best explaination I've seen - thanks for that.

I fixed it in a similar vein, by simply replacing my receiver with a new one (...which I believe has 1080p as the standard output). So: there's no easy software fix, you need an upstream device to report the "correct" resolution.

It'd be nice if OS X understood and re-scanned when the device changed or was updated (as it's probably doing when the signal goes off and on...) but that might be technically complicated for a variety of reasons. As you say, get a device in the middle that sorts it, whether it's your box-o-tricks or a new receiver 🙂