One of 4 USB-C ports not working

CAWjr

macrumors 6502
Original poster
Jan 19, 2010
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Atlanta, GA
I have a refurbished 15" MPB with touchbar that I got in April. I have only been using it as a laptop until this weekend when my wife Brough home two Acer 27" monitors from work. I bought two USB-C to DVI cables to plug the monitors in & they work like a champ. I the plugged in power into the front left USB-C port & it would cut in & out. I moved it to the back port & it worked fine. I then tried to plug in my USB hub to the same port & it would not work.

With nothing else plugged in, that port has worked fine for power, USB sticks, etc. But it seems that when I have two monitors plugged in the right side ports and power in the back left port, the front left port goes to crap. As a test case, I just unplugged the power, left the monitors plugged in on the right side, and the lower left port still appears to be dead.

I know that the easy answer is to bring it to the Apple Store to have them look at it, but before I do that, I wanted to see if anyone else has had issues with the ports not working when you have other things plugged into all of them.
 

New_Mac_Smell

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Oct 17, 2016
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Does it work if you plug a single monitor on each side as opposed to two on one? I believe they user separate controllers, one for each side, so that could be the issue. Worth trying before faffing around with Apple support.
 
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CAWjr

macrumors 6502
Original poster
Jan 19, 2010
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Atlanta, GA
Does it work if you plug a single monitor on each side as opposed to two on one? I believe they user separate controllers, one for each side, so that could be the issue. Worth trying before faffing around with Apple support.
I currently have both monitors plugged in on the right side ports & they work fine. Plugging a monitor into the "dead port" doesn't work.

I unplugged everything & just plugged the power in the "dead port" and now it's acting up with nothing else plugged in. A trip to the Apple Store is definitely in my future.
 

New_Mac_Smell

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Oct 17, 2016
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I currently have both monitors plugged in on the right side ports & they work fine. Plugging a monitor into the "dead port" doesn't work.

I unplugged everything & just plugged the power in the "dead port" and now it's acting up with nothing else plugged in. A trip to the Apple Store is definitely in my future.
Does it do this after a fresh restart (It's more likely a H/W issue but worth seeing if it's S/W).

And you haven't plugged in any 3rd party chargers or cheap eBay stuff into that port? I have heard of a few being DOA but not many failing like that. If you have plugged in something like a cheap power bank into that port then I wouldn't tell Apple...
 
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CAWjr

macrumors 6502
Original poster
Jan 19, 2010
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Atlanta, GA
I just got off the phone with Apple & they had me troubleshoot it a few different ways that included rebooting. The port is DOA.

As for third party things, I use Aukey USB-C to USB-A adapters, but those work fine. The two USB-C to DVI cables I'm using for the monitors came from Amazon and they work fine on the non DOA ports. I've only used the included Apple power pack, so I'm not concerned about any of my accessories having fried the port. Good advice to avoid telling them if I had though. :)
 

michaelbraun

macrumors newbie
Jan 8, 2018
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0
Hi CAWjr,

Found this discussion when trying to fix exactly the problem you had. Two USB-C to HDMI plugged in on the left, and front port on right no longer working. Very weird.

What did Apple ultimately do for you?
 

CAWjr

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Original poster
Jan 19, 2010
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Atlanta, GA
What did Apple ultimately do for you?
I brought my MBP into the store, they sent it back, said they could not reproduce the issue. Thankfully I had a video on the laptop of the issue happening. They gave me a whole new machine with the same serial number.
 
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michaelbraun

macrumors newbie
Jan 8, 2018
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0
"Could not reproduce." Geez. Glad it worked out for you! I will make sure to take a video before sending it off anywhere. I am going to give Apple a call now. Thank you for posting about the issue!
[doublepost=1515437173][/doublepost]Well, good news. I was able to reset the SMC and now everything is working: Both monitors and all four USB-C ports. What a relief!!
 

William Forrest

macrumors newbie
Dec 23, 2017
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I brought my MBP into the store, they sent it back, said they could not reproduce the issue. Thankfully I had a video on the laptop of the issue happening. They gave me a whole new machine with the same serial number.
It seems I have a very similar problem with my 2017 Macbook Pro 15 with touchbar. The left/front USB- C is acting squirrley. I plugged a Gigabit ethernet cable into it, and was happily connected, but after circa 10 minutes the lights went out and the connection was gone. I tried resetting the SMC to no avail. Now, I find that port won't connect to a Sansa Clip, the blue light on my USB-C to USB adaptor doesn't come on.

All three other USB-C ports seem to be working fine. I'm actually encouraged that you also had your front/left port go bad, now I hope my other three will keep working at least for a while.

My failure is pretty reliable, but I don't want to take my machine in and find the repair people can't see that problem. Before taking it in, I'll record a video of it's blue light failure (while the other three ports show the blue light just fine).

I just found: when that pesky left/front USB-C fails to communicate, I can plug my power cord into that port, and it charges my battery just fine. In the interim, I'll use that port for power and the other 3 ports for everything else.
 

CAWjr

macrumors 6502
Original poster
Jan 19, 2010
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Atlanta, GA
I recommend shooting a video of the behavior & going to the store sooner rather than later. The warranty is only good for so long & the problem isn't going to fix itself.
 

poorcody

macrumors 6502a
Jul 23, 2013
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546
For those with a dead or intermittent port, have you tried flipping the cable/device when you plug it in? I have one USB-C port on my 2016 MBP that only works when cables are plugged in on way. When I flip it, it appears dead.

Might explain why Apple couldn't "reproduce" the problem, if they only plugged in things one way...