Pegasus 2 R4 not mounting

  • Last Post 23 September 2020
Carsten Schwarting posted this 20 September 2020

I am running a Pegasus 2 R4 attached to a MAC Pro running macOS High Sierra 10.13.6.  The Pegasus drive stopped mounting after a software upgrade.  It doesn't even show up under "System - Hardware - Thunderbolt".   Hardware seems fine.  I read many threads citing same problem but none helped.  I tried disconnecting / reconnecting.   Nothing.  It's as if nothing is connected to the computer.  Please help.

Order By: Standard | Latest | Votes
Ranjith kumar posted this 23 September 2020

Hi Carsten,

-Kindly let us know after what software update, Pegasus stopped working.

-what is the power light status of the Pegasus

-Have you checked with swapping the Thunderbolt cable at different port of Pegasus and Mac

Kindly reach us through for quick response.

Thank you,


Promise Team

Carsten Schwarting posted this 23 September 2020

Hi Ranjith --

Thank you for taking the time to reply.  I solved the problem.  It was unrelated to the software update. 

The black cable that came with the original Pegasus failed.  I replaced the cable with a new Thunderbolt cable, and everything started working immediately.

For the benefit of other users who might be experiencing the same issue, the failure in this case was unusual.  The drive worked intermittently before the cable fully failed.  The cable was not moved or pinched.  I did read some other posts where people suggested switching cables, but I disregarded those posts.  I've never had a cable fail spontaneously, I didn't want to spend them money on another cable just to troubleshoot, and it sounded like a perfunctory step.  It isn't!  Based on what I read online, maybe the OEM cable has a higher than usual failure rate, but I don't know that for sure.  Regardless, check your cable!