2012 Mac Mini + Dell U3818DW

AbSoluTc

macrumors 601
Original poster
Sep 21, 2008
4,413
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I have a 2012, 6,2 Mac Mini server - i7, 16GB ram, 512 SSD. I connected my u3818dw monitor to the mini via mini DP to DP cable and it picks it up just fine. However, if I restart/shutdown, the mini will not boot. Screen stays blank and "searching for signal". I can boot fine using the HDMI to HDMI (mini to monitor). Only issue with that, is the resolution is capped at 1080p.

Is this just a limitation of the Mini? I have to turn the machine off physically to reset it after it has booted with the monitor connected via DP. It will not output any signal either via DP or HDMI until it's turned off fully.

Anyway around that?
 

Celerondon

macrumors 6502a
Oct 17, 2013
680
124
Southern Cal
I have a 2012, 6,2 Mac Mini server - i7, 16GB ram, 512 SSD. I connected my u3818dw monitor to the mini via mini DP to DP cable and it picks it up just fine. However, if I restart/shutdown, the mini will not boot. Screen stays blank and "searching for signal". I can boot fine using the HDMI to HDMI (mini to monitor). Only issue with that, is the resolution is capped at 1080p.

Is this just a limitation of the Mini? I have to turn the machine off physically to reset it after it has booted with the monitor connected via DP. It will not output any signal either via DP or HDMI until it's turned off fully.

Anyway around that?
Okay, I want to understand how you finally get the monitor to work with the mini after it fails to boot. After a restart or shutdown the mini will not boot, correct? Then the only way you can successfully boot the mini and use the Dell u3818dw is to launch the OS with the HDMI display port activated.

Here are some ideas:
  1. Try a different mini DP cable.
  2. Check your monitor port settings. (Toggle your DP 1.2 setting in the Dell menu)
That Dell should work fine with your mini. :apple: A 2012 Mac mini is not DP 1.2 capable. Poke around in your menus and reset to factory settings if you can't find anything else.
 

Neodym

macrumors 68020
Jul 5, 2002
2,054
611
With an LG 34UC98W (native: 3440x1440) I had to scale down to 2560x1080 to run the monitor properly (i.e. without scrambled picture in the lower third of the screen) with my late 2012 i7 mini. After a PRAM reset it would work for a few days and then return to the same problem.

What seems to have it fixed for me (*knocks on wood*), was to upgrade from El Capitan to High Sierra. IIRC Apple switched to a new graphic subsystem there (Metal2?), which seems to have been improved in the right places.
 
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AbSoluTc

macrumors 601
Original poster
Sep 21, 2008
4,413
2,760
Okay, I want to understand how you finally get the monitor to work with the mini after it fails to boot. After a restart or shutdown the mini will not boot, correct? Then the only way you can successfully boot the mini and use the Dell u3818dw is to launch the OS with the HDMI display port activated.

Here are some ideas:
  1. Try a different mini DP cable.
  2. Check your monitor port settings. (Toggle your DP 1.2 setting in the Dell menu)
That Dell should work fine with your mini. :apple: A 2012 Mac mini is not DP 1.2 capable. Poke around in your menus and reset to factory settings if you can't find anything else.

Only way to get it to work is boot with an HDMI cable, then switch over to DP. Display works fine after that. You just can't restart with the DP cable plugged in with the display :(

The display also doesn't have DP settings to change either.
 

sublunar

macrumors 65816
Jun 23, 2007
1,356
799
I have problems with Display Port and 2560x1440 monitor - occasionally the monitor doesn't pick up the signal although my 2012 Mini is booted. It's a similar issue to my Thunderbolt to Dual Link adaptor connected to my Dell monitor. I usually leave my Mini asleep but it occasionally doesn't wake with similar issues.

I've never tried to connect a HDMI monitor to it though - I don't have a 1080p display.

I'd rather 'fix' this by getting a new Mini though :)
 

Celerondon

macrumors 6502a
Oct 17, 2013
680
124
Southern Cal
Did you try a different cable yet? By different I mean a different brand. Sometimes this sort of problem is caused by a lack of handshake/communication between the computer and display.

Also: I like Neodym's suggestion. With or without plug-and-play communication the OS has to be compatible with the monitor. Perhaps that new Dell needs a tweaked (updated) OS to work with your 2012 mini.
 
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