iMac won't offer display mirroring option when connecting to HDTV with Thunderbolt to HDMI cable

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Level 1

6 points

iMac won't offer display mirroring option when connecting to HDTV with Thunderbolt to HDMI cable

I have an iMac, and am trying to connect to my HDTV to use as a second display (mirror). I am using a cable with a Thunderbolt connector at one end, and an HDMI on the other. I know the cable works because I have used it with my MacBook on other TVs. When I use this on my MacBook, I simply open displays, and between the tabs marked "Display" and "Color" there is always an "Arrangement" tab to select. When I try this same setup on my iMac, the only two tabs I can see are "Display" and "Color" - the option to mirror disdplay (or recognize the HDTV in any way) simply doesn't exist.

I would welcome any help. Thanks much, Doug.

iMac, Mac OS X (10.7.5)

Posted on Apr 16, 2014 6:23 PM

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Answer 1

Cmndrred Author

Level 1

6 points

Apr 19, 2014 3:54 PM in response to den.thed

The TV is a little older, a Vizeo, probably 5 years old. It has 3 HDMI inputs and I've tried a couple of different ones (and configured the TV input appropriately). Is it possible that the iMac isn't displaying the "arrangement" or "mirror" options because it isn't recognizing the TV due to an issue on the TV end? I know the TV's HDMI ports work because I can plug PS3 and other devices into them just fine. But if the Mac doesn't see anything on the other end, would it even offer me the arrangement/mirror controls? That's all I can think of.

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Answer 2

den.thed

Level 9

77,074 points

Apr 16, 2014 7:24 PM in response to Cmndrred

The preference panel for the Extended Desktop display will only show Display|Color.

The preference panel for the Main Display should still have all three, Display|Arrangement|Color.

If you click on the Main Display preference panel and select Arrangement, you should see a box to select Mirror Displays.

Can't remember exactly because the menu bar option has changed in Mavericks, but if your running Lion or Mountain Lion you should be able to Show a Display Icon on your Menu bar that allows for quickly switching between Extended Desktop and Mirroring.

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Answer 3

Cmndrred Author

Level 1

6 points

Apr 16, 2014 7:50 PM in response to den.thed

I did add the display icon to my toolbar, but when I click it and open display preferences (or do this from System Preferences), the panel that pops up looks like the one below; the one I am wanting to see is precisely what you show me...with the Arrangement tab and Mirror Displays box.

User uploaded file

My software is up to date (Mac OS X 10.7.5). The TV I am trying to link to has 3 HDMI inputs, so it should be able to handle what I am trying to do. I just can't get the Mac to recognize it. I have also tried rebooting the Mac before and after the TV is turned on, no difference.Gotta be something simple/stupid, but damned if I can figure out what.

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Answer 4

den.thed

Level 9

77,074 points

Apr 16, 2014 8:23 PM in response to Cmndrred

What model is your iMac...? see > How to identify iMac models

If it is an older model that has a Mini DisplayPort instead of a Thunderbolt Port, then that cable will not work and you will need a > Mini DisplayPort to HDMI Adapter, plus an HDMI cable.

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Answer 5

Cmndrred Author

Level 1

6 points

Apr 19, 2014 3:33 PM in response to den.thed

I mave an iMac12,1 - its a little under 3 years old. The port I'm plugged into has the little lightening bolt (thunderbolt) logo above it, so I am assuming it is true Thunderbolt, but don't know muchabout this.

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Answer 6

den.thed

Level 9

77,074 points

Apr 19, 2014 5:01 PM in response to Cmndrred

OK, yes your Mid 2011 has a Thunderbolt port.

Reset > the System Management Controller

1. Shut down the computer.

2. Unplug the computer's power cord.

3. Wait fifteen seconds.

4. Attach the computer's power cord.

5. Wait five seconds, then press the power button to turn on the computer.

and the > NVRAM and PRAM

1. Shut down the computer.

2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.

3. Turn on the computer.

4. Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.

5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.

6. Release the keys.

Then try connecting the TV to the iMac.

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Answer 7

ali-b-kl

Level 1

4 points

Apr 20, 2016 5:00 AM in response to den.thed

I was trying to connect a MacBook Pro, Retina, 13 inch, late 2012 to a Samsung monitor with VGA port only via Mini Display Port to VGA adaptor. I wasn't getting the arrangement tab, just display and colour. After re-starting and holding down command, option p and r as you suggested it appeared. Great advice, thank you.

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Answer 8

Sep 10, 2016 10:16 PM in response to Cmndrred

Matthew

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