Thunderbolt 2 External HD won't mount in one of my 16" MBP M1Pro ports...

[ddavid]

I have a 16" MacBook Pro M1Pro and am using a couple of external Thunderbolt 2 hard drives connected using Apple's TB2-TB3 adapter. The disks will not mount using the Thunderbolt4 port closest to the MagSafe Power connector! I have tried the other two Thunderbolt4 ports and the disks mount fine. I also tried plugging in a USB-C flash drive into all three ports and it mounts right away, as well as an external monitor using USB-C.

I believe I read that the new MacBook Pros have a separate controller for each of the three ports, although the USB-C peripherals mount fine using all three. Any ideas?

 

[Fishrrman]

"The disks will not mount using the Thunderbolt4 port closest to the MagSafe Power connector! I have tried the other two Thunderbolt4 ports and the disks mount fine."

The way forward can be found in your own words in the post above.

Fishrrman's credo:
Use what works for you.
Ignore what doesn't work.

 

[ddavid]

"The disks will not mount using the Thunderbolt4 port closest to the MagSafe Power connector! I have tried the other two Thunderbolt4 ports and the disks mount fine."

The way forward can be found in your own words in the post above.

Fishrrman's credo:
Use what works for you.
Ignore what doesn't work.

Is your uncle the doctor who, when told by a patient "Doc, it hurts when I do this!" replied "Well, stop doing that" and then sent him a bill?

 

[ddavid]

The point is, does anyone know why one discreet port might not mount a disk and others do? Has anyone heard of an issue with either the Thunderbolt 2 to 3 adapter, or the Thunderbolt 4 ports on the MacBook Pro that would explain this? Any ideas on how to diagnose this and narrow it down to either a defective dongle or a defective port? If it is a port issue, I'd like to address it asap while the laptop is still new.

 

[Goodrich]

i had a usb c charging overheat on that port and found it became disabled.

I reset the controller with a set of magic keypresses when the system is off that I found on the internet and the port came back.

 

[ddavid]

i had a usb c charging overheat on that port and found it became disabled.

I reset the controller with a set of magic keypresses when the system is off that I found on the internet and the port came back.

Interesting. Was the port completely inop? Do you remember the keyboard incantation you used?

 

[Fishrrman]

I was reading over at dpreview.com about a user who had an issue that was similar to the OP's -- one USBc port seemed to be not working.

He took it to an Apple Store, and they diagnosed it as a "failed logic board", and would repair it thusly.

Have you considered taking it to an Apple Store genius bar?

 

[Goodrich]

You could try resetting the SMC or nvram or … first. Google is your / was my friend.

 

[ddavid]

I was reading over at dpreview.com about a user who had an issue that was similar to the OP's -- one USBc port seemed to be not working.

He took it to an Apple Store, and they diagnosed it as a "failed logic board", and would repair it thusly.

Have you considered taking it to an Apple Store genius bar?

Ugh. Yeah, I had considered it, although I like to wait until I know as much about whatever issue before I contact the Genius Bar, or Apple Tech Support. Like everything with MacBooks, a new logic board is the remedy.

I found the dpreview thread you referenced…

Macbook Pro USB cable problem: Mac Talk Forum: Digital Photography Review

Expert news, reviews and videos of the latest digital cameras, lenses, accessories, and phones. Get answers to your questions in our photography forums.

www.dpreview.com

 

[You’re not me]

Is the Thunderbolt 2 drive powerEd through the port?

 

[ddavid]

Okay… I tried this using the TB4 port closest to the MagSafe charger and the HD mounts fine. However, it’s the difference between the ports that concerns me…

[ ]————-[ ]————- [TB2/3]————💻 👎

[ ]————-—————- [TB2/3]————💻 👍

 

[ddavid]

Is the Thunderbolt 2 drive powerEd through the port?

No, both drives are powered individually with power bricks.

 

[Fishrrman]

Going by reply 11 above...

The port works with ONE drive, is that correct?
But DOES NOT WORK if you daisy-chain TWO drives, is that correct?

Perhaps it's a cable problem.
or
Some kind of "incompatibility" between the first drive and the second?

Can you "swap the drives around in the chain"?

 

[ddavid]

Going by reply 11 above...

The port works with ONE drive, is that correct?
But DOES NOT WORK if you daisy-chain TWO drives, is that correct?

Perhaps it's a cable problem.
or
Some kind of "incompatibility" between the first drive and the second?

Can you "swap the drives around in the chain"?

Merry Christmas

It works daisy chained on TB4 ports Left Lower and Right, but not Left Upper. I tried plugging in just one drive, a G-Drive, and it works on all ports. Next I tried swapping the two Thunderbolt cables and it works in all three ports as well. My G-Drive only has one TB port and my LaCie has two TB ports so my chain has to go from the G-Drive>LaCie>MacBook Pro.

Swapping the cables worked, but what bothers me now is the difference between the ports.

 

[Fishrrman]

Based on your tests, my take is that all the USBc ports are working as intended.

The "glitch" you're experiencing is -- in my 2 cents opinion -- due to cabling issues or perhaps just "the mix" of drives and cables (that either works, or does not work)...

 

[Rad]

Thunderbolt 2 simply does not work on a M1 Mac using Thunderbolt 4. Thunderbolt 3 Macs are compatible with Thunderbolt 2, but Thunderbolt 4 specification specifically states that Thunderbolt 2 will NOT work. Found out the hard way when my very expensive Pegasus Thunderbolt drive array would not mount anything. It can see the enclosure but the drives do not mount.

Is Thunderbolt 4 Backwards Compatible? | Cable Matters Blog

With a new cable standard comes the age-old question: Is Thunderbolt 4 backwards compatible? Read on to find out.

www.cablematters.com

 

[kentzh]

Thunderbolt 2 simply does not work on a M1 Mac using Thunderbolt 4. Thunderbolt 3 Macs are compatible with Thunderbolt 2, but Thunderbolt 4 specification specifically states that Thunderbolt 2 will NOT work. Found out the hard way when my very expensive Pegasus Thunderbolt drive array would not mount anything. It can see the enclosure but the drives do not mount.

Is Thunderbolt 4 Backwards Compatible? | Cable Matters Blog

With a new cable standard comes the age-old question: Is Thunderbolt 4 backwards compatible? Read on to find out.

www.cablematters.com

My Pegasus Thunderbolt 2 R8 and R4 can be recognized and used by the 16-inch M1MAX through Thunderbolt3 to Thunderbolt2 cables. But first you need to go to the official Pegasus website to download the supported drivers and applications. Did you do that?

 

[ddavid]

Thunderbolt 2 simply does not work on a M1 Mac using Thunderbolt 4.

I have not found that to be true. I have two Thunderbolt 2 hard drives that work as expected on my M1pro using Apple's Thunderbolt 2 to 3 adapter. (with the exception of my port anomaly)