Q: Mini display port to HDMI problem

It just does not work.

There is no options in "Display preferences" for external monitor till you connect it.

And connection is not working.

Before I bought the 3rd cable it worked.

I bought 3rd cable, most expensive in shop, and it worked well yesterday. Only sound did not work, but that was something already.

Today in the morning I tried to wake up a laptop and external monitor does not work anymore.

I tried to reboot laptop, monitor, used another cables for connection. Now nothing is working, not even cables which worked before.

To be sure it is not monitor - I connected Apple TV and it works just fine.

When I connect macbook through Apple TV it is laggy and does not cover 100% of the screen and not possible to work because of timeout.

So I cannot work now.

And I am very angry on Apple, because it seems they don't care about this issue.
This post have been created 6 years ago and still not solved!

And btw:

- Macbook air 13", 2013 late

- Yosemite 10.10.5

- Dell S2415H

You know what man. I have this same issue with my late-2011 model. Only two things are finicky. One: the thunderboltport (hdmi-to-thunderbolt) isn't working. There's no signal from my computer of the tv's and monitors i plug into. To top if all off. This started when I upgraded to Yosemite. THAT was a good idea. "Sarcasm"

I have my problem fixed by buying 4th cable.

I just went into shop with my laptop and monitor and tried few cables right there.

An Apple store?

and what if your monitor cannot be moved?

(too large and/or mounted permanently)

So I'm going to throw in too. I use a mini display to HDMI cable (NEET), no adapter, purely for running films and catch up tv from the mac to TV. Been using it for a couple of years now, no issues. This week I noticed it didn't pick up initially. Dismissed it.

Then tonight. Nothing.

When I plug the lead into my macbook pro (late 2009) it flickers but that's it.

Detect display detects nothing.

My TV recognises there's an HDMI lead plugged into it. I'm guessing the mbp does because it flickers when the lead is plugged in but that is it.

I've done a safe boot and a nvmar whatever thing. No change.

I'm going to see if I can get a lead tomorrow.

If that works I will post here.

Any suggestions would be appreciated.

UPDATE:

I ordered the exact same mini display port to HDMI lead (not adapter) from the same site as before. It's a NEET adapter. Cost me 13 quid in total. Plugged it in. Problem solved. My mac now recognises AND mirrors with the TV.

The difference is the plug fits into the MBP port much more snugly now.

The original cable is 3 years old.

Hurrah!

Thank you... solved my problem..

This morning my iMac suddenly failed to recognize the mini display port to HDMI driven ASUS display I have been using for the last month.

No amount of replugging video cables, restarting the computer, or turning on and off the screen did anything.

However, I did eventually find a solution:

1. Turn off the Computer.
2. Turn off External display.
3. Unplug both ends of the video cable (and any other video cables if you are using 2 or more external displays).
4. Unplug the power cable to the external display.
5. Reset the pram on the computer by pressing the power button and holding Command Option P R until you hear a second power chime.
6. Login and wait for the computer to finish loading.
7. Open system preferences.
8. While holding the option key, open "Displays".
9. Plug the power into your external display.  (It will have been long enough to fully power cycle it by now.)
10. Plug the video cable into your computer.
11. Plug the video cable into your external display.
12. At this point point it may recognize your display.  However, if it does not: hold the option key and observe the "Gather Windows" button change to "Detect Displays".  Click this button.
13. You should now see both displays.  You may have to go into "Arrangement" to disable mirroring and rotate/scale the screen as necessary.

Hope this helps!

I am a new Macbook Air User.. Just bought a 4K 29.90 Mini DP to HDMI adapter and like many here.. simply can't get my TV to detect the signal..

found this very old discussion and tried most of the methods to change the settings...nothing work.

So today i went back to exchange..the salesman tested the adapter on a windows laptop and found it to be working perfectly...

But he was very helpful in the end as he ask me to try another 19.90 adapter which rated Full HD only that had usage example of Macbook or iMac on the packaging .. did an exchange and use the 10 difference to get a wire mouse.

Went home Plug in my macbook air and connect to my LED TV... if works perfectly immediately..

So my conclusion is not all Mini DP to HDMI adapter are compatible to Macbook.

My tips if you are getting Mini DP to HDMI adapter for the 1st time..

1) Get those that are Full HD only 1920 x 1080 and avoid those 4K HDMI.

2) Check on the packaging if it is specially designed for Macbook or iMac.

The brand of the 19.90 adapter i am using now is Mazer

THANK YOU   IT REALLY WORKS

Thank you!! best advice ever defo worked!

My problem is the same HDMI-remote TV connection problem recited on this help page but somehow older or more basic. I'm running Snow Leopard 10.6.8 on a desktop iMac that is at least five years old. Unlike what you describe, my System Preferences menu doesn't display two windows or two little blue screens. It shows only the available resolutions with two buttons at the top, Display and Color, and two at the bottom Gather Windows and Detect Displays. Whatever I do, the TV monitor simply says No Signal. Now the really odd part, I had the HDMI-TV setup working back in June. Then left the country for a couple of weeks, shutting down everything and pulling the plugs. Now I can't get it to work again. Any idea why?

Wayne in Tokyo

Thank you! That worked for me!