How to fix thunderbolt to vga display port? I have a MacBook Air (13-inch, Early 2014) and a third-party thunderbolt to vga adapter. I have had the adapter for over 2 years now and it has given me no problem at all. Suddenly, this week the macbook stopped detecting different displays. Here is what I have done to solve the problem:


Tried combinations of different screens, different VGA cables with the adapter
Checked if the adapter was working via a colleagues laptop (adapters seem to be working fine)
Tried different third party adapters
Resetting SMC and NVRAM
Updated the OSx from El Capitan to Mojave
Performed first aid and hardware check from Disk Utility
Tried installing the MiniDisplayVGAFirmware update 


Nothing seems to work. On El Capitan the screen of the laptop would blink, after plugging the adapter to the Thunderbolt port, as if it recognised the screen but would not recognise the screen. On Mojave the screen does not even blink

I still have to try it with the official Apple Adapter but I do not want to buy it and realise that that is not the problem.

What do you think could be the issue? How can I fix it? Any suggestions would be appreciated.

Thanks in advance!
If the adapter works fine on another Mac (second bullet point) then it is not the adapter. If you have tried a number of different adapters on your Mac and all of them do not work then I would then assume that is it one of two things:


A hardware issue with your Mac. EG a bad lightning port.
An issue with the installation of macOS on your Mac.


From your description of the symptoms I am leaning towards #1. However since backing up your Mac, re-formatting the HD, reinstalling the OS and restoring your files is a free (if tedious) procedure that would eliminate whether or not it is an OS issue I would start with that.

And if that fails you likely need to take the Mac in for repair.