Having HDMI trouble after updating 2012 Mini from El Capitan to Sierra

[Osamede]

I updated my 2012 Mac Mini HTPC/home server from El Capitan to Sierra. Since then, I have been having trouble with the HDMI.

The unit seems to be operating normally, because I have no trouble accessing file shares, Plex server etc on it. However when I try to turn on the TV and use the TV as a screen for the unit, it wont display. This is the case whether I link via my receiver as usual, or if I plug the Mini directly to the TV. Changing HDMI cables doesn't work. My Blu ray player has no problem with HDMI link when playing directly to the TV or via the receiver.

Rebooting (hold the power button down on back of Mini) seems to be the only way to get the Mini to actually connect to the TV. But once I shut down the TV or change inputs, we are back to square one: the HDMI wont link and display the screen.

So this seem to be strictly a HDMI freezing issue.

Anyone experience this, or know of a solution?

 

[jpietrzak8]

Can I ask how old your TV is? I've got a fairly ancient low-end Sanyo hooked up to one of my Minis; the Mini can connect to it on bootup, but if I switch the TV off and on again, the two won't connect to each other (although I am able to change inputs).

I haven't yet found a solution to the problem. Like you, I found that rebooting will get it to work again; also, entering and leaving sleep mode works. Finally, unplugging and replugging the HDMI cable seems to get the two talking to one another again.

But my guess is that my TV just wasn't given the software/hardware needed to properly interact with a computer over HDMI.

 

[Osamede]

It's nothing to do with the receiver or the TV (2011 Denon receiver and a 2011 Panasonic top of the line TV). Both working flawlessly for more than four years, HDMI, ARC and everything, with that Mac Mini....until I applied the update from El Capitan to Sierra some weeks ago.

Rebooting works, but I have external thunderbolt drives connected to the unit and that cant be good for them. Besides which I cant reboot everytime I want to use the thing.

 

[jpietrzak8]

It's nothing to do with the receiver or the TV (2011 Denon receiver and a 2011 Panasonic top of the line TV). Both working flawlessly for more than four years, HDMI, ARC and everything, with that Mac Mini....until I applied the update from El Capitan to Sierra some weeks ago.

Question: does unplugging / replugging the HDMI cable allow the two to start talking to one another again? (This would at least help me, as it would show this is a software problem on the Mac side rather than a hardware problem somewhere... ) Thanks!

 

[Osamede]

Question: does unplugging / replugging the HDMI cable allow the two to start talking to one another again? (This would at least help me, as it would show this is a software problem on the Mac side rather than a hardware problem somewhere... ) Thanks!

Unplugging/replugging has no effect in my case.

My Mac Mini will only connect to the TV display at boot/reboot. But once the Mini sleeps or the TV display is switched to another input, the Mini wont resync.

When doing the same things with my blu ray player, the TV and the receiver all connect or reconnect correctly.

 

[jpietrzak8]

Unplugging/replugging has no effect in my case.

Thanks! So, my problem is probably hardware then; yours software. Sorry I can't provide more help...

 

[fischersd]

Unplugging/replugging has no effect in my case.

My Mac Mini will only connect to the TV display at boot/reboot. But once the Mini sleeps or the TV display is switched to another input, the Mini wont resync.

When doing the same things with my blu ray player, the TV and the receiver all connect or reconnect correctly.

So, you're saying you can't introduce the problem just by unplugging / re-plugging the HDMI cable?
I have almost the same setup - except my receiver is a Pioneer SC-25. I don't have my mini going to sleep though - ever.
That's what it's sounding like to me - that when the mini puts the HDMI port into sleep mode, it's not sending the appropriate signal to the receiver to revive the port. (so, the easy fix is to change your power settings to have your display always on)
My Panasonic is a plasma (think it's a few years older than yours as well), so I tend to turn it off when not in use - it generates a hell of a lot of heat (65")

Edit: Maybe Apple implemented something in the HDMI spec differently (more up to date) with their Sierra driver. Maybe see if there's a firmware update for your receiver that may have the two in sync with sleep mode again?

Edit2: Actually, mine should be pretty similar...it's the 2009 model V10

 

[Fishrrman]

Well, you could always just "go back to El Capitan"…

Just sayin' ...

 

[George Dawes]

I had the same problem with 2 mini's - ones perma bricked by el crapitan and the other i managed to put yosemite on

It's an OS bug to do with the power cycling in the gpu ( from what I gleaned from trawling the net for info )

Basically the mini goes into power saving sleep mode and screws up the hdmi out - whether you turn sleep off or not

 

[Osamede]

I seem to have solved the problem. Not sure which one if these it was but I changed the energy saver to sleep at 3 hours instead of never. And applied the most new OS update I found showed up in my updates.

 

[George Dawes]

I fixed it on another mini by setting the display to sleep after 4 hours

Not the mac just the video out - then wake it up with the keyboard / mouse