I purchased some TB adapters for my 15" CTO Late 2013" Retina (i7 / 16GB / 1TB Flash / dGPU) and I have some problems with a port. 1. Original Apple Thunderbolt to Ethernet adapter 2. 3rd party generic (from Amazon) Thunderbolt to HDMI adapter. As you may know, the Retina's have two Thunderbolt 2 ports and I think one of them is dead. If I plug in the adapters in the first port (the one near the Magsafe) everything works great. Signal goes to the TV or the internet connections works. Now, if I plug in the adapters in the second port (the one near the USB port) nothing happens, sort of. a) My Mac does not detect the Ethernet Cable no matter what. Tried restarting, updated this morning to 10.11.4 (had the problem yesterday on 10.11.3). b) My Mac does detect my office TV (this is why I bought the cable - office presentations & meetings) but there is no signal to the TV. I can change the Resolution, refresh rate and even select the TV's speakers to play music but no signal gets to the TV. (check the screenshots - OS X detects it but the TV displays "no signal") Again, the first port works great. Only the second one is messed up. So what to do ? Did u guys had this problem ? This is a 2 year old machine so no warranty Thanks ! --- Post Merged, Mar 22, 2016 --- Update : 1. Under System Report both Thunderbolt port are shown and I guess this is a good thing. 2. Pressed ALT (Option) in Display Pref to show the hidden button "Detect Displays" ; clicked it, still broken. 3. Reseted NVRAM (PRAM) and SMC, still broken. 4. Changed the HDMI Cable and the input, still broken. 5. Tried connecting it via HMDI, works great just like the first port. I cant figure out what the hell is going on with the second port. Please help me. If I take it to Apple they will just quote me an insane price (because this is the high end MBP, top of the line) for a logic board replacement. Because the computer sees the port and the Mac sees the TV with the second port I don't think a logic board replacement is needed. --- Post Merged, Mar 22, 2016 --- Update 2 : Apple Hardware test says everything is OK. This made my day just a tiny bit better. Srsly thinking now it's some weird software glitch. I've read this past hour like crazy and A LOT of people said that Yosemite killed their port. Now this Mac came with Mavericks, I upgraded to Yosemite and now El Cap ; like I said in the title this is the first time I'm using them so I really don't know if they worked in Mavericks. The people affected said they solved the problem by downgrading to Mavericks and then upgrade back. I really don't have time for this.. and I'm not 100% sure the port worked fine in the older versions of OSX. Like I said, firs time using it on El Cap.