Force Mac to detect displays?

Question

I have a Mac mini in a somewhat complex home-theatre setup. Often the Mac won't correctly recognize the TV as a display. The TV will just report "No signal". There are two methods to recover from this state.

Unplug the display cable from the Mac and plug it back in
Sleep the Mac and wake it up again.

Both are a bit cumbersome. Is there any way to force the Mac to re-detect or re-initialize it's displays? I've tried Command-F2 and a couple AppleScripts but nothing seemed to work.

score 22 · Answer 1 · answered Mar 06 '13 at 21:10

22

Just press the option key while you're in Displays in System Preferences. You'll get a Detect displays button (bottom right).

answered Mar 06 '13 at 21:10

nkkollaw

334

score 16 · Accepted Answer · answered Jan 15 '16 at 11:18

This is really old but I found a solution that still works in OS X 10.11.2:

hit cmd + "brightness up" for display detection and cmd + "brightness down" to switch between mirror and extend display modes. It seems to be the brightness keys and not necessarily the F1 and F2 key.

score 2 · Answer 3 · answered Feb 25 '10 at 16:14

2

In the displays prefplane, there is a checkbox "Show displays in menu bar". If you check it, you get this somewhat strange new icon in the menu bar that has "Detect Displays" as its first option.

answered Feb 25 '10 at 16:14

bastibe

3,912

score 2 · Answer 4 · answered Nov 19 '09 at 03:25

2

Here is an AppleScript someone wrote for 10.4 which may help you:

http://www.insanelymac.com/forum/index.php?s=&showtopic=59163&view=findpost&p=457644

answered Nov 19 '09 at 03:25

ridogi

2,987

score 1 · Answer 5 · answered Feb 25 '10 at 16:08

1

In the displays prefpane there is a button 'detect displays' (But I'm on a MacBook, not a mini with a TV.)

answered Feb 25 '10 at 16:08

Justin Love

1,006

Force Mac to detect displays?

5 Answers5