Security Updates May Disable USB-C/ThunderBolt Port

[yukari]

I have Mac Mini 2018 and MBP 2018. After seeing this thread I refuse to update my 2018 Mac Mini, but I updated my MBP 2018. It "lost left inner" USB-C use for SSD but strangely it still works if I connect the power supply.

So I just switched my power supply and external SSD connection. I have NOT tried SMC reset, as I can live with just switching the connections.

 

[shadowfax--]

I have Mac Mini 2018 and MBP 2018. After seeing this thread I refuse to update my 2018 Mac Mini, but I updated my MBP 2018. It "lost left inner" USB-C use for SSD but strangely it still works if I connect the power supply.

So I just switched my power supply and external SSD connection. I have NOT tried SMC reset, as I can live with just switching the connections.

SMC reset is very easy just go for it.

 

[MarciaFunebre]

I know now from several people that SMC reset does not always work. Some were lucky, but this is not guaranteed. Strange thing is that the same thing happens whether you are updating Mojave (security update) or you update Catalina to 10.15.4. The same thing happens. On a variety of different machines.

 

[matt0578]

I have the same problem on my 13-inch MBP 2019 with two Thunderbolt ports after installing Security Update 2020-002. It was the right port that died on this computer. Charging works, though, as reported by others. SMC reset didn't fix the issue.

ETA: NVRAM reset did fix it.

 

[yukari]

I have the same problem on my 13-inch MBP 2019 with two Thunderbolt ports after installing Security Update 2020-002. It was the right port that died on this computer. Charging works, though, as reported by others. SMC reset didn't fix the issue.

ETA: NVRAM reset did fix it.

Thanks for letting us know. I'll have to try NVRAM reset.
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Just did the NVRAM reset, and voila! Like @matt0578 said, it works!
Thanks @matt0578!