how to hook up HDMI

[Marilyn G]

I have a 2017 iMac Sierra 10.12.5 and i want to connect it to my big tv using a USB-C to HDMi adapter. the Geek squad guy said just plug it in and it will automatically work. From the display menu box it doesnt show any hdmi options. When i called a person in TVs said that the newer macs can only work with a smart tv. HELP! My old one worked with this tv just fine until the hard drive crashed. I need this for my preschool.

 

[Lunder89]

Don't worry. It will work just fine. Get the adapter, plug it in. Your Mac will register the additional screen, and send a signal to it. From System Preferences > Display, you can choose how to set it up. The display icon in the menu bar is not guaranteed to show up. And nothing in the Preference panel will change, until another display is connected.

Here are a few pointers, that might help making it work every time.

• Turn on the TV on HDMI channel (Input, Source or whatever it is called), if possible (some Samsungs won't open HDMI signals that are not active)
• Connect the adapter to HDMI cable
• Connect the adapter to the Mac

Can't explain why, but sometimes it needs something in the other end, to figure out what signal to send, if it can't figure it out, it might not send something at all. At which point unplugging and then plugging the adapter back in, should resolve the issue.

 

[casperes1996]

I have a 2017 iMac Sierra 10.12.5 and i want to connect it to my big tv using a USB-C to HDMi adapter. the Geek squad guy said just plug it in and it will automatically work. From the display menu box it doesnt show any hdmi options. When i called a person in TVs said that the newer macs can only work with a smart tv. HELP! My old one worked with this tv just fine until the hard drive crashed. I need this for my preschool.

Doesn't work on non-smart TTVs? That's the most ridiculous thing I've ever heard. SmartTVs change nothing in terms of Display logic compared to the usual standards.

If what the other post says doesn't work, it might have to do with your specific USB-C to HDMI adapter. Which one did you get? There's a lot of fuzz about which converts work properly and which don't (though that's mostly about Display Port converters, not HDMI.)

 

[Marilyn G]

well, I talked to Best Buy IT help, and of course when she walked me through it it worked. The smart tv was a load of crap, guess they wanted me to buy a tv. BUT, an IT girl walked me through it and it worked I could get the display box where I chose the display size etc, until I shut everything down so I could rearrange the cables out of the way. when I turned everything back on the tv says no signal and the mac doesnt give me that same box. It has a choice of mirror built in retina display, OR mirror LG tv, ORuse as separate display...I still cant get anything to the tv. I need to be able to see on the monitor and the tv. I am so confused, I dont think this should be this difficult. I did turn everything off and reconnect like Lunder89 suggested, UGGG

 

[casperes1996]

well, I talked to Best Buy IT help, and of course when she walked me through it it worked. The smart tv was a load of crap, guess they wanted me to buy a tv. BUT, an IT girl walked me through it and it worked I could get the display box where I chose the display size etc, until I shut everything down so I could rearrange the cables out of the way. when I turned everything back on the tv says no signal and the mac doesnt give me that same box. It has a choice of mirror built in retina display, OR mirror LG tv, ORuse as separate display...I still cant get anything to the tv. I need to be able to see on the monitor and the tv. I am so confused, I dont think this should be this difficult. I did turn everything off and reconnect like Lunder89 suggested, UGGG

Mirror to LG-TV should display the same on both the TV and the native display. – Tried reconnecting the cable on each end? (One end at a time). If you've already had it working once, we know it definitely can work.

 

[gsahli]

I think the important suggestion that Lunder89 gave is the one about setting the Input or Source on the TV. In many cases, the TV's remote control is the only way to set that.

 

[Marilyn G]

Thanks for all your help. It still just shows the LG as a black screen, when I chose the HDMI setting on the tv, it says connecting (like it should) but its just black. I ordered Plugable USB-C to HDMI 2.0 Cable (6'/1.8m) for 2016 / 2017 MacBook Pro, Dell XPS 13 & 15, Thunderbolt 3 & More (Supports 4K 60Hz Displays up to 3840x2160@60Hz) because when it was connected for that short time the mac monitor would blink on and off, maybe a short?? I'm using a Belkin 4K/60Hz USB-C adapter connected to my old HDMI cable that used to work just fine with my old system. This is making me kinda nuts!!
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Don't worry. It will work just fine. Get the adapter, plug it in. Your Mac will register the additional screen, and send a signal to it. From System Preferences > Display, you can choose how to set it up. The display icon in the menu bar is not guaranteed to show up. And nothing in the Preference panel will change, until another display is connected.

Here are a few pointers, that might help making it work every time.

• Turn on the TV on HDMI channel (Input, Source or whatever it is called), if possible (some Samsungs won't open HDMI signals that are not active)
• Connect the adapter to HDMI cable
• Connect the adapter to the Mac

Can't explain why, but sometimes it needs something in the other end, to figure out what signal to send, if it can't figure it out, it might not send something at all. At which point unplugging and then plugging the adapter back in, should resolve the issue.

Thanks, I did this again today, but same outcome, the mac shows the display box for the monitor and the one for the LGtv, but the TV is screen black.

 

[Lunder89]

If you are using an unoriginal HDMI adapter/cable, that might be the problem. I work at a school, where we have purchased quite a few Mini-Display to HDMI cables, for our projectors. And these cables only worked for like a week or so, before what you describes started happening.
Buying Apples USB-C to HDMI adapter, and using a normal HDMI cable will make things work a hole lot better.

 

[Marilyn G]

well I got my new cable (usb-c and Hdmi all in one cable), It popped right up and I did my happy dance. But then I shut down everything...turned off tv, shut down iMac...turned everything back on and only a bright blue screen on tv! I unplugged the USB-C and replugged it and it worked??? is my Mac haunted?

 

[casperes1996]

well I got my new cable (usb-c and Hdmi all in one cable), It popped right up and I did my happy dance. But then I shut down everything...turned off tv, shut down iMac...turned everything back on and only a bright blue screen on tv! I unplugged the USB-C and replugged it and it worked??? is my Mac haunted?

Depending on the TV, the order in which things are turned on (TV first or Mac first) can have an impact on whether it'll register the connected cable, if it's already in when you boot up the devices. Therefore, unplugging and replugging the cable fixed it. I imagine that's what's going on

 

[Lunder89]

well I got my new cable (usb-c and Hdmi all in one cable), It popped right up and I did my happy dance. But then I shut down everything...turned off tv, shut down iMac...turned everything back on and only a bright blue screen on tv! I unplugged the USB-C and replugged it and it worked??? is my Mac haunted?

No your Mac is not haunted, as I wrote, non-Apple USB-C video output cables is most likely the culprit.
But as long as it is working

Otherwise, try to follow the instruction set I gave earlier, id does iron out a few kinks.

 

[Marilyn G]

Thanks so much for your help.

 

[Lunder89]

You are welcome