Why I cannot get 3840*2160 res on my new late 2014 Mac mini?

I am joining the discussion because many of us out there have this problem.

Att he top of the thread, it says "branched to a new discussion" but clicking on it yields:

"Access to this place or content is restricted. If you think this is a mistake, please contact your administrator or the person who directed you here."

This is strange. Apple?

Specifically, I have the same problem with the following details:

- Hisense 50" 4k monitor

- Brand new Mac mini out of the box, no other software, just doesn't work (I selected 24Hz but still doesn't show higher than 1080p resolutions)

- The same HDMI cable, TV HDMI port work just flawlessly 4k with a Sony Bluray player when using its image viewer app. TV announces 2160p, so it does normally work. It is NOT the TV.

- I never saw 2160p when booting

Moreover, I should add I ONLY bought that Mac Mini to drive the 4k TV. I can live with significant lags as it is for demo and similiar use cases. If Apple isn't responding to the issue, I'll return my Mac.

Update,

there is a chance my dealer sent an old model (2013) which doesn't support 4k according to Apple. If true, then this wasn't Apple's fault. I'll post an update.

FInal update. Got my new 2014 Mac Mini now, works w/o problem with my 4k Hisense TV now.

Maybe, worth a note ...

Initially, boots in 4k but then switches to 1080p after the OS is loaded.

To get 4k at the OS level, one has to do this:

1. Switch to 24Hz, 25Hz or 30Hz under Scaling

2. Now, the 2160p resolution emerges in the list (3840x2160)

3. Select it

4. Note how 50Hz and 60Hz now disappeared from the list

It is straightforward to do. But maybe not as intuitive to everybody as Apple may think.

A table with resolutions in rows and frequencies in columns, with radio buttons where a possible combination is encountered, would be a better, more intuitive UI than two drop down lists ...