2nd Screen Won't Register @ Startup

Feb 11, 2010
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OK, anyone have this problem? I posted on this a few weeks ago, tried two suggestions from ya'all but they didn't work. Here's the problem:

I have an iMac running version 10.6.2 with a 2.66 GHz Intel Core 2 Duo, 4gigs, 1067 MHz DDR3 blah, blah, blah...

I have a second screen hooked up as I do a lot of graphics stuff and use 2 monitors in my work flow.

OK, that all being said here's the problem...

EVERY time, and I mean every time, I start the machine it will not register the second screen. To get the second screen to be seen by the iMac I have to unplug the screen from the jack behind the computer and plug it right back in. Then and only then will the iMac recognize the second screen.

Is there any way I can get this darn computer to recognize that a second screen is present without unplugging it and re-plugging it to the back of the iMac??

Now, if I shut down the imac and then restart it while everything is still warm, the second screen will read fine. But if I leave the system off for a few hours it acts as I described above. Further more it has done this since the beginning. There never was a time when this set up worked properly.

My last question… could it be my converter plug? The little plug that goes into the back of the imac and to the second screen? Could it be bad? Maybe?


Well-known member
Staff member
Jan 23, 2008
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Keller, Texas
Your Mac's Specs
2017 27" iMac, 10.5" iPad Pro, iPhone 8, iPhone 11, iPhone 12 Mini, Numerous iPods, Monterey
You have nothing to lose by trying another adapter. However, it may be a problem with your external monitor, not the adapter or the iMac. Have you tried using another monitor to see if the same thing happens? That would kind of narrow things down so you can troubleshoot further.


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