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Level 1

0 points

My mac pro with dual monitors keep switching sides after reboot

Hi all,

I am having a really weird issues with my Mac Pro after I installed Mountain Lion. I have dual ACD Monitors. Every time I reboot, the monitors switch sides. In other words, the monitor that is in front of me with the dock would switch to the other monitor and vice versa after I reboot. When I reboot again, it switches back again. This is extremely annoying. I have had to switch the inputs on the back of my computer every time.

Mac Pro, OS X Mountain Lion (10.8.2)

Posted on Nov 21, 2012 4:54 PM

17 replies

RatVega™

Level 4

2,005 points

Dec 11, 2013 2:59 PM in response to link6009

link6009 wrote:

I hate to burst my own bubble here, but I recently added a 3rd monitor, and now I'm getting the same inconsistent monitor switching between my second and third monitors.

Here's my set up:

Mac Pro, OSX 10.8.2

2x2.26 GHz Quad Core Intel Xeon

16 GB RAM

Three Dell ST2420L display monitors

What seems to be happening now is that I get three identical 'color' display profiles. The first one seems to stay on the same monitor, but the second and third monitors now switch at random. I can't seem to get them to stay in any particular order.

Any suggestions or new approaches for solving this would be greatly appreciated!

I've been doing multiple monitors since the late '90s and never seen this problem... then I realized I always profiled the monitors seperately (early on they were often mismatched) and each monitor profile had a unique profile and profile name, even if I started with the same vendor profile. No guarantees, but worth the effort of re-naming.

good luck

Sep 12, 2014 7:23 AM in response to Neeper78

I am having the same problem with 2 Mac Pro computers and an iMac -- all with dual monitors. My dock keeps jumping to the worn monitor - and I have to use system preferences - monitors - to re-do it. Even thought the dock is on the wrong monitor, the white bar is shown above the correct monitor. This started with OS 10.9 .....

Any fixes from Apple??? I do all the updates ....

My mac pro with dual monitors keep switching sides after reboot