2018 Macbook Pros Thunderbolt issue with external drives

Discussion in 'MacBook Pro' started by zombat119, Jan 16, 2019.

  1. zombat119, Jan 16, 2019
    Last edited: Jan 16, 2019

    zombat119 macrumors newbie

    Jan 16, 2019

    Can anyone confirm their Thunderbolt ports on the right side of their 2018 Macbook or Mbp works like it should?

    I tried with multiple external drives. I went to the apple shop, together with one of the guys from the genius bar, we tried on multiple machines. Seems to work on non t2 chipped machines. Just wanted to see any users here have similar issues.

    Of course, if that's an existing issue with the 2018 Mbp or T2-chipped MacBooks, would be good to warn users not to connect their external drive using the right side Thunderbolt. As I have lost data on 2 external drives.

    I have reported this to Apple, they told me so far only 2 users reported this. There are no updates from their engineering department as I was told. I am reluctant to re-order another Mbp just in case this is a Thunderbolt hardware issue rather than firmware.

    The following is the video on how you could replicate the issue on your machine.

  2. anpaman macrumors member

    Feb 13, 2018
    Does it also happend to Macbook Pro 2018 with High Sierra ?
  3. Ploki macrumors 68040

    Jan 21, 2008

    I tried with a USB3.0 dongle, i don't have a spare drive right now.

    I did it like this?
    - format as test1 on left side, create new folder, eject
    - format as test2 on right side, create new folder, eject
    - connect back to left side

    is this correct?

    This way the drive didn't corrupt
  4. zombat119, Jan 16, 2019
    Last edited: Jan 16, 2019

    zombat119 thread starter macrumors newbie

    Jan 16, 2019
    Hi, unfortunately all the 2018 machines I tried with was preloaded with Mojave
    --- Post Merged, Jan 16, 2019 ---
    Yes that is correct.

    As soon as you format the drive on the right side thunderbolt ports, its already corrupted. Once you erase, it doesn't mount automatically like it should. The left side works perfectly.

    If you connect a working external drive into the right side ports, it will mount. As soon as you unmount, it will corrupt the external drive.
  5. Ploki macrumors 68040

    Jan 21, 2008
    I did, but as I said I tried with a dongle.
    I erased and created a folder on the right side, ejected, then plugged into the left side and it showed up fine.

    I will try to find a hard-drive which has nothing important on to try it
  6. chrfr macrumors 604

    Jul 11, 2009
    I'm not getting corruption from disks connected in either side. I have not tested with a Thunderbolt disk but have used USB-C drives without any problem.
  7. zombat119 thread starter macrumors newbie

    Jan 16, 2019
    Fair enough. I forgot to mentioned, I tried both USB-C Cable as well as dongle.
    --- Post Merged, Jan 16, 2019 ---
    Are your machine 2018 t2 chipped with Mojave 10.14.2?
  8. Clix Pix, Jan 16, 2019
    Last edited: Jan 16, 2019

    Clix Pix macrumors demi-goddess

    Clix Pix

    Oct 9, 2005
    8 miles from the Apple Store at Tysons (VA)
    No problem here with my 2018 15" MBP (i9/1 TB/32 GB RAM, Vega 20, currently on Mojave 10.14.2)). I have used older external mechanical drives, G-Drive Portable SSDs, Samsung T5 USB-C SSD drives and the new Samsung X5 Thunderbolt 3 SSD. I've used them on both sides of the machine. The charging cable is plugged into one of the ports on the left side of the machine and I have several times plugged in an external drive on that side plus a second one on the right-hand side of the machine in order to transfer data from one drive to the other. Actually, the other day I had three external drives plus the charging cable plugged in so that I could more conveniently swap data among them, and everything worked flawlessly. I always take a quick look at everything to be sure all the data transferred successfully and only after that do I go ahead and eject the drives. I do not leave my external drives plugged in all the time, only when I actually need to use them.
  9. zombat119 thread starter macrumors newbie

    Jan 16, 2019
    Thank you very much. I will go to the Apple store to give it a try again, and potentially re-order another MBP.
  10. Diazepam macrumors member


    Nov 24, 2018
    I don't know how closely my usage scenario resembles yours, but for what it's worth ...

    With my 2018 MBP, with Mojave 10.14.2 installed, I have used ...

    - 4 different (old) USB 2.0 flash drives (connected thru A-C adapter)
    - 1 old 2TB Western Digital spinning ext. drive (USB 3, I think) (connected thru A-C adapter)
    - 1 new Kingston USB-C (3.1) drive

    (I have also connected all these drives to the laptop with High Sierra installed on another partition)

    MBP 13" w/ Touch Bar, 16GB RAM, 2.3 GHz Core i5, 512 GB SSD

    I have connected the drives on either side of my MBP. No problems whatsoever.

    I think you got a bad piece. Get it exchanged ASAP.
  11. Ploki macrumors 68040

    Jan 21, 2008
    Yeah, 13" 2018
  12. chrfr macrumors 604

    Jul 11, 2009
    Mine is a 2018 2.3GHz i5 13".

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