2016 MBP weird port failure

[creativesmith]

Originally posted this in Apple Discussions, but haven't gotten much response. Perhaps someone here would like to chime in?

On our 2016, 13" MBP, a peculiar port failure issue.

When we attach an external USB-C drive to the FORWARD, right port—the system fails to mount it. The drive is getting power, as indicated by the drive's light. It does not, however, appear in the Finder, nor Disk Utility. When that same drive is plugged into the REAR right port, it performs correctly. When we try a second USB-C drive in the FORWARD port, it too receives power but the system cannot mount it. Using different cables does not a difference.

But… when we plug one drive in the REAR port and the other in the FORWARD port, both function normally. Huh? Isn't that weird? So is it a controller issue, a short, something on the OS side?

If we try a combination of the FORWARD right port and either of the LEFT ports, the FORWARD right drive remains unmounted.

Have reset SMC, rebooted, experimented with a Guest account, yet results remain as above.

Any thoughts, please?

Thanks

 

[Fishrrman]

At 6 years old, it's not worth a motherboard replacement -- too much $$$.

You seem to have found at least one solution that works.

Fishrrman's Rule #3 of computing:
Use what works for you.
Ignore what doesn't work.

 

[spiderman0616]

Sounds like you fried something on the motherboard with a static shock or surge or the port just failed on its own. It's 100% not worth fixing. USB has always been susceptible to this and I've done it more than once myself. Do you live in a dry, staticky environment regularly? If so, a static pad might be a good investment for your desk so that you can ground yourself before handling the metal laptop.

Just a wild stab based on my own experience. Not saying this is definitely the issue with your machine.

 

[creativesmith]

Sounds like you fried something on the motherboard with a static shock or surge or the port just failed on its own. It's 100% not worth fixing. USB has always been susceptible to this and I've done it more than once myself. Do you live in a dry, staticky environment regularly? If so, a static pad might be a good investment for your desk so that you can ground yourself before handling the metal laptop.

Just a wild stab based on my own experience. Not saying this is definitely the issue with your machine.

Thanks for the reply. Yes, agreed—not worth repair.
Interesting that you asked about the dry environment. No, not dry and staticky here, at least not to the extent that I'm aware of it. (Within the context of global warming, would love to find someplace cool and dry.)
Though I'd likely not fully understand the details of the answer, am still curious about what's happening within the machine. Why would the forward port work only when the rear port is occupied. Inserting the rear plug jiggles something on the motherboard, reconnects an otherwise broken contact? Or, use of that rear port heats up something, causes a bit of expansion, reconnects a broken connection? Yeah, I know, doesn't really matter.
So, time to buy a new machine.

 

[spiderman0616]

Thanks for the reply. Yes, agreed—not worth repair.
Interesting that you asked about the dry environment. No, not dry and staticky here, at least not to the extent that I'm aware of it. (Within the context of global warming, would love to find someplace cool and dry.)
Though I'd likely not fully understand the details of the answer, am still curious about what's happening within the machine. Why would the forward port work only when the rear port is occupied. Inserting the rear plug jiggles something on the motherboard, reconnects an otherwise broken contact? Or, use of that rear port heats up something, causes a bit of expansion, reconnects a broken connection? Yeah, I know, doesn't really matter.
So, time to buy a new machine.

It's so frustrating when things like this happen, because you just know you're opening a can of worms trying to figure out what's going on. Another option if you don't really NEED a new computer right now is to just get a hub to replace the bad port, but I know how people generally feel about dongles.

On the other hand, if you're the type who doesn't like upgrading until absolutely necessary, this could be the perfect excuse you're looking for. We are talking about a fairly old laptop with a butterfly keyboard though. My personal tendency would be to recycle it and get one of the new ones, which are all FABULOUS computers.

 

[creativesmith]

At 6 years old, it's not worth a motherboard replacement -- too much $$$.

You seem to have found at least one solution that works.

Fishrrman's Rule #3 of computing:
Use what works for you.
Ignore what doesn't work.

Oh, I like that Fishrrman's Rule #3! Yes!
Unfortunately, this is one of those niggling curiosities that keeps pestering me.
But will do my best to heed your advice, ignore, and move on.
Thanks for the reply.