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Member Since: Dec 22, 2006
Location: Texas, where else?
Posts: 26,041
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Mac Specs: 15" MBP '06 2.33 C2D 4GB 10.7; 13" MBA '11 1.8 i7 4GB 10.10; 21" iMac '13 2.9 i5 8GB 10.10; 5s & 5c

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ISSUES: There are several issues you may run into once you have connected your Mac to the TV.

1. There is nothing on the screen or the TV is not detected.

First, if you are using a notebook Mac - you need to plug it in to power, not run it off the battery.

A) Make sure you have picked up the TV remote and hit the Input button to change to the port matching the one your Mac is connected to.

B) Once you know the TV is on the correct input and still nothing, disconnect all cables and/or adapters... yes, even if you are certain they're connected and then reconnect them. I can't even begin to tell you how often this does it.

C) Next, open up System Preferences - Displays and click the 'Detect displays' button.
If the external is being detected, there will be 2 separate display windows if you're using a notebook, one for your notebook and a second for the external monitor/TV. The second window could be on the external or it could be hiding - if you only see one window on the screen, move it and see if there is another hiding behind it.

D) If you don't see the 2nd window, put a check on the 'Mirror displays' option.

E) If you are getting the second display window, try some different resolutions to see if you can find one that works. Open up the owners manual for your TV and verify the resolutions it will accept through the port you're using. Most TVs will have a section close to the end of the manual listing the accepted resolutions for each input port.

F) Some TVs have their own proprietary video enhancement stuff like Cinemavision or some such nonsense. Check yours and turn anything like that off.

G) After that, some TVs require that they be turned on related to the computer in a specific order or they do not pass the EDID info properly. You may need to turn on the TV first, then the computer (this is the typical requirement) or vice versa.

H) Next, try a SMC reset - link.

I) Still no picture, the last step is going to be trying a different adapter, cable and/or attaching your Mac to a different TV to determine if you have a bad adapter, cable, port on the Mac or port on the TV.

(You could try DisplayConfigX or SwitchResX to see if adjusting the resolution and frequency per your owner's manual helps. See links in # 2 below.)

****Bottom line, there are some TVs that are not going to display a picture via HDMI from a computer. They just are not passing fully compatible EDID info along. Some Samsung sets are notorious for this. At that point, it's time to move along and go with the VGA connection which almost all TVs still have today.

If you are determined to get your HDMI working, you can grab the DVI Doctor from You can read about it here.****

2. The menu bar and dock are cut off OR I have a black border all the way around the screen

This issue is related to overscan. For a pretty good run down of what overscan is and why it exists you can check out the Wiki. The first couple of paragraphs will give you enough background without getting into all the technical mumbo-jumbo.

The menu bar and dock are cut off:

The best way to deal with this issue is to turn overscan off on your TV. You'll need to open up your Owner's Manual and do some reading. The problem, very few TV sets have this option available from their menu. Some will call it 'Overscan', 'Just Scan', or some variation thereof.

The next is to open up System Preferences - Displays - head for 'Options' on the TV preferences window and uncheck overscan. You will now have a black border around all 4 sides of the screen. If you are lazy like me, you'll live with this.

To fix this, you have two options. You'll need to grab SwitchResX or DisplayConfigX and create a custom resolution for your TV. The how to for this is outside the scope I'm currently prepared to go into at this time. A little searching and you should find some fine tutorials for either one of them. (Besides their own sites, the AVS forum is a great place to start and you might check these - SwitchResX - DisplayConfigX.) For a starting point resolution use 1768x992. This should work for any TV that will accept 1080 input and includes practically all 720p sets.

3. I have a duplicate copy of my desktop or All I have is the background and nothing else.

There are two modes available with your external display, mirroring and extended desktop.

Mirroring does just what it says. It mirrors or provides the exact same desktop on both displays.

Extended Desktop provides a 2nd desktop separate from your primary display. You can drag any apps you wish to use on this display from your primary screen and use one screen for watching a movie and the other for browsing the web.

To change between the 2 modes, open up System Preferences - Displays and then the Appearance tab.

Mirrored Mode
If you want the same thing on both screens, you'll put a check in the 'Mirror displays' box.

Extended Desktop Mode
If you want to make use of the additional screen real estate, you'll uncheck the 'Mirror displays' box to enter Extended Desktop mode.

Once you're in Extended Desktop mode and still in Displays preferences, you'll have a second window that will show you a picture of your 2 displays.
You can move them around to match the way you have your physical displays setup and making it easier to move your cursor from one screen to another.
You'll also notice one of them has a white bar at the top of it. This represents your menu bar. You can drag and drop the menu bar from one screen to the other. Moving it to the external display will make it the primary display whenever it's connected. You do not need to go back in and change it when it's disconnected. Your Mac will know your single display is the primary when the other one is not connected.

4. I'm not getting any sound

Once everything is connected properly, make sure you head to System Preferences - Sound and select the headphone output or for the newer models that support audio via the mini displayport, the device you have it connected to.

To learn which connection you need to use on your TV for audio - See the very next post starting with "Second".

The new mid 2010 Mac Mini is the first Mac with a HDMI port supporting audio out.
Beginning with the late 2009 iMac, the mid 2010 notebooks and Mini, the mini displayport supports audio.

4B. Volume is very low on my exterior speakers.

Realize the headphone jack that you're using for audio out is not a true "line out" jack. What this means to you: you're going to need to turn the volume up on your Mac.

If you have the volume muted or turned all the way down on your Mac, you're not going to get any audio on your external speakers. If you have it turned down too low on your Mac, then you'll have to turn the volume up too high on your external speakers, possibly causing noise and/or distortion.

For my HTPC, I generally keep the volume on my computer set to 75-100%. Then you'll be able to control the volume from your TV or AVR remote much better - without the need of turning it up too high. With some experimentation, you can find the appropriate level to set the volume on your Mac, so that it more closely matches the other devices plugged into your TV/AVR.
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