External Hard Drive won't mount in Sequoia 15.3

Contact Pegasus support since their software is not loading.

you must be a level 10 as your response makes no sense at all. Open what activity? I've got two external hard drives not mounting after upgrading to Sequoia 15.3.1 while three other are mounted just fine. This happens after every upgrade.

I'm having the same issue. My timemachine drive has worked for years until I upgraded to 15.3 and now it won't mount, won't show up on disk utility. If it's connected (USB direct to M1 Macbook Pro or via powered hub) it just flashes. If its connected it won't let the machine even reboot or diskutility show anything. After the POST/login the macbook just sits, blank, until I pull the drive then it will continue to restart.

I look at the system report and when connected to the powered hub the power readings

 Location ID: 0x01132000 / 7

 Current Available (mA): 500

 Current Required (mA): 500

 Extra Operating Current (mA): 0

So I'm open to any suggestions to get this one running again.

Thanks

Kinda figured that was the answers. But as it is occasionally with a Mac there is a magical command buried deep in the operating system somewhere that produces a ‘ta-da’ and problem is solved.

thanks for info

J

My Pegasus R32 will not mount. The Drive lights up. I could not install Pegasus DEXT driver. Permissions for it was allowed on Privacy and security. I was on apple support and they couldn't fix it. This was a 2021 MacBook Pro with m chip (recently had most of the system replace after spilling soup on it). It was connecting prior to the accident. I next tried to install the drivers on a 2025 MacBook Air 15 and the same problem. It seems an software problem.

Both running Seqoia 15.3.1

Same issue. Thought my 2 TB Seagate drive had gone bad (yes, she's old), bought a new 2TB SSD drive, accessed files from cloud backup and it worked for a couple weeks and then it no longer would show up and disk utility would not mount it. I'm at a complete loss as to why a brand new drive won't mount.

Is it aUSB2 drive?

Is it USB2 powered Hub..M1 Mac with USB3 should have 900 mA available

Looks like it.

What are my options?

Unfortunately the only other machine I have access to for the foreseeable future is another MBP running 15.3.1 and it’s not able to access it’s external drive either

Best of luck my friend, do let us know the outcome.

m1 MacBook Air same issue

Same hardware, same issue here

Apple are beginning to **** me off on a regular basis, seriously looking at other options at this point and I've been using their platforms since the eighties

where do y stand on dunking the hd in tea (min of 15 mins)?

y really seem to know what you're on about and i for one am just grateful y stopped in to share this invaluable knowledge, yo