I purchased a SABRENT EC-HD2B 2.5" & 3.5" Black SATA I/II/III USB 3.0 USB 3.0 to SATA I/II/III Dual Bay External Hard Drive Docking Station It works, but appears to be impossible to re-mount a drive once it has been ejected.

On a Windows 10 64 bit system, this docking station appears in Device Manager as "Sabrent Dual SATA Bridge SCSI Disk Device" (Compared to most external drives which are listed as "USB Device" under Disk Drives)

The USB eject/reconnect does not work with this UAS dock. After ejecting the drive (aka safely remove), any drive in the dock will never be recognized again until the computer is rebooted. After I eject, turn off the docking station power and/or unplug USB, the drive (or drives) will not be recognized again when reconnected. Device Manager shows it as a Storage Controller named "USB Attached SCSI (UAS) Mass Storage Device" and has this error: "Windows cannot use this hardware device because it has been prepared for safe removal but it has not been removed from the computer. (Code 47) To fix this problem unplug this device from your computer and then plug it in again."

Even after powering down the docking station, unplugging and replugging the USB connector multiple times, the error remains and the drive/controller is not recognized. Attempting to disable and re-enable the UAS device in Device Manager results in the message: "Hardware has changed - you must restart the system"

This issue defeats the purpose of an external drive - being able to remove and reconnect without restarting the system.

Except for this problem, the dock works well. I'm looking for additional docking stations, and am trying to determine if this is just a bad product, or if there is a Windows limitation preventing the re-mounting of UAS. Does anyone have a UAS drive dock that can be removed and remounted without rebooting?

Device Manager - Normal Operation enter image description here

Eject Prompt: enter image description here

Device Manager after Sabrent ejected and USB disconnected: enter image description here

Device Manager after Sabrent is plugged into USB again and powered up: enter image description here

Detail of Device Manager error message after re-connecting Sabrent: enter image description here

  • Have you checked device manager? If you disconnect the USB connection the docking station all devices that belong to it should be removed from device manager. If not something may be wrong with the USB connection between PC and docking station.
    – Robert
    Aug 7, 2021 at 20:35
  • Yes the "USB Attached SCSI (UAS) Mass Storage Device" is gone from Device manager when unplugged or powered down. However when plugging back in, it is not usable - the error messages are described above.
    – tim11g
    Aug 7, 2021 at 21:59
  • > Even after powering down the docking station, unplugging and replugging the USB connector multiple times, the error remains and the drive/controller is not recognized. -- can you confirm that you removed all power (all power cables and the USB cable, at the same time) from the device from a period of time before reconnecting it? While that should not be necessary in a well-designed device, at least it should rule out the device somehow maintaining state.
    – Bob
    Aug 8, 2021 at 18:49

1 Answer 1


While I cannot say whether your dock is "defective", this is not an inherent limitation of Windows.

I have just tested three separate UASP-compatible adapters on Windows 10 20H2, and all of them behave as expected: after a safe-eject, physically reconnecting the USB cable causes all three adapters to be recognised again the same way they were the first time. This behaviour is consistent with what I recall from many years of using such devices on Windows.

Tested devices:

  • StarTech S251BPU313 with an ASMedia ASM1351 controller (VID_174C&PID_1351)
  • StarTech USB312SAT3CB with an ASMedia ASM1051 controller (VID_174C&PID_55AA)
  • Orico 2139U3 with a JMicron JMS578 controller (VID_0080&PID_A001)

That said, my experience is limited to unpowered/bus-powered devices (2.5" adapters powered purely by USB 5V, no separate 12V power as needed for 3.5" HDDs). I do not expect externally-powered devices to behave differently; even poorly-behaved ones should be fully reset if disconnected from all power sources.

If you have tested completely depowering your device (removing all external power sources and the USB connection simultaneously) then that should rule out any issues on the device side. At this point I would suggest:

  1. Testing what happens if you disconnect/reconnect without a "safely remove"
  2. Testing against a different computer, if possible
  3. Testing against a virtual machine on the same physical host, if possible

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