Thunderbolt Does Not Detect Display

I have a Late 2013 MBP 15inch... Thunderbolt port works with the ethernet adapter, BUT it will not with the Video adapter. The Displays will not even notice the connection...

Though when I disconnect the cable from the MBP, the screen goes to black for half a second as acknowledging that the disconnection has occurred, while the cable is connected, NOTHING appears int the Thunderbolt or Display info as connected...

What is funnier, is that trying the SAME video adapter and the SAME displays, on a 13inch late 2013 MBP worked PERFECTLY!!!

Any ideas? I have already tried reseting everything I could... I even reinstalled the system!!!

HELP!!!!

Hello,

I have the same problem since I purchased a "MBP retina 15 end 2013" beginning of may 2014. At the beginning the video was switching between the display and the MBP. I bring the display to the store, they tested it and it was ok. Test with a MB Air, no one read the logs and various traces I did, no written report from the support. After the Mavericks 10.9.4 it was a little better, I had less screen switch. Now, since 3 days the display remains black, only power goes to the computer but no thunderbolt link , so no display and no wired eth. The day after it started OK, and today it is the same problem. Once I disconnected everything from the power and wait 10 minutes , then it came back. But now this does not have any effect. It reminds me a condenser problem I had with a TV soundbar. I have to say this is very frustrating to buy a fisrt class hardware which does not work properly, until now I am very disappointed with this thunderbolt display. I purchased both units , the MBP and the display at the same time and subscrided the Apple care , which in that case is totally useless it seems, because if I want an apple store support , I have first to book a slot in their overloaded agenda, then bring all the hardware to the store etc... Not very efficient, at least for the client. In conclusion, I should not have purchase this display, the computer itself is fine.

friguyb, EXACTLY as you say it... We buy "top notch" tech, and get these kind of problems???? Hope somebody stands up and tells us how to fix this (if there is a way). In my case as well, the MBP works perfectly in any other way.

My display has still some weird behavior sometimes but less than before. May be it is linked with the way I start it up. Actually I do not close the laptop immediately, I wait at least 30 seconds then close the laptop. I am now running OS X 10.9.5. i will see if there is progress on this side.

SOLUTION:

I have struggled with this as well for some time and I have found a solution that should work for most:

Follow these steps and it should work for ya:

1. Turn off your TV and unplug the thunderbolt cable from computer.

2. Go to System Preferences/Security & Privacy

- under the firewall tab, turn off the firewall, if you cannot, then just click on the lock to be able to make changes icon

3. Now, while your TV is still off, plug the thunderbolt cable into your computer and the other end to your TV HDMI either through an adapter you have or whatever.

4. Then, turn on your TV, select source or what have you, and select HDMI and your TV should now recognize and display the mac screen.

5. You can go to System Preferences/Displays and you will see that it now recognizes the TV. From here, you can mess with your resolutions etc.

This is the only process that worked for me.

Try it 😉

Also, try closing the screen down on your laptop after doing all of the above when your tv is off.

With all the research I have done and how many people are having this same issue (myself included), the problem is either with the Apple's operating system or the Macbook Pro itself that just does not detect VGA connected monitors after sleep mode. The ONLY solution is to restart the computer and/or (in my case what worked for me as well) was to unplug the VGA to Thunderbolt, plug into another laptop (in my case my sons Macbook Air), then remove and replug into my Macbook Pro (2015 model).

My DVI to HDMI works flawlessly but my second monitor (VGA to Thunderbolt) does not. As another test to prove my theory, I connected my sons second monitor with DVI to Thunderbolt and that too works flawlessly as a second monitor on my setup...even after sleep mode over and over again.

So the solution is to NOT use VGA for MacBooks! Unless you like to restart and/or shut down and reboot every time.

Sadly that seems the case with my thunderbolt to hdmi cable. My Mac mini was not detecting the second display on the thunderbolt port. I tried everything and I put a little pressure on the cable near the port and then I got picture. Not sure if this is a port issue or a cable issue yet.

Thank you so much! I literally read every forum to fix this and ours was the only ting that worked!

Hi, I have a thunderbolt to DVI a straight through connection, and this doesn't seem to work and I don't why???