Unable to change resolution on second monitor (invalid resolution)

Question

Unable to change resolution on second monitor (invalid resolution)

Started today, Im unable to use my second monitor with Yosemite Mac Book pro mid 2012. When I plug the second monitor (samsung 32'') the mac is sending the incorrect resolution, the monitor shows a message saying that the resolution is not compatilbe... and Im unable to change the resulution, as I can not see anything on the second screen.

If I turn mirroring on, then change the resolution to 1080i, works fine. But I dont want mirroring, I want extended desktop, when I unclick mirroring, same error. and again, unable to change resolution as i can not see anything on the screen.

Was working before (for almost 2years), and started today. I already restarted several times.

Help please, thanks in advance

MacBook Pro (Retina, Mid 2012), OS X Yosemite (10.10.3)

Posted on May 4, 2015 11:23 AM

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Answer 1

Linc Davis

Level 10

209,535 points

May 4, 2015 11:54 AM in response to javierfromirvine

See the last paragraph of this support article. If that doesn't solve the problem, you are likely to be using the wrong kind of adapter to connect the display. For third-party displays with a resolution greater than or equal to 2560x1440, you need a powered dual-link DVI adapter.

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Answer 2

May 4, 2015 1:01 PM in response to Linc Davis

Thanks for the response, but that solution does not help, as i have no access to change the resolution on the second monitor.

The connectors are ok, if I select mirroring, it works. Thanks

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Answer 3

Linc Davis

Level 10

209,535 points

May 4, 2015 1:14 PM in response to javierfromirvine

Back up all data. Quit System Preferences if it's running.

Triple-click anywhere in the line below on this page to select it, then copy the text to the Clipboard by pressing the key combination command-C:

~/Library/Preferences/ByHost

In the Finder, select

Go ▹ Go to Folder...

from the menu bar. Paste into the box that opens (command-V), then press return. A folder should open. If it does, look for a file with a long name that begins "com.apple.preference.displays2". There may be several such files. Move them all to the Trash.

Log out or restart the computer. Test. If the problem is resolved, empty the Trash and recreate your settings in the Displays preference pane.

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