Finder not recognising external SSD

[paieye]

DiskDrill recognised the external drive yesterday, but neither it nor Disk Utility can find it today. Unplugging and replugging, changing USB ports &c. makes no difference.

 

[Bigwaff]

Reboot. Try again. What is file system type of ext SSD?

 

[paieye]

Rebooting has made no difference. I think that the file-system is Mac Journaled.

 

[gilby101]

Try different cable.

That you are using Disk Drill, suggests that you think it is corrupt or faulty. Is that right?

 

[paieye]

No, I started using it yesterday purely because Disk Utilities, although it recognised the drive, was not correctly showing its capacity. DD immediately recognised the drive, and correctly showed its capacity to be 320 gb. But today, neither of them is recognising it.

 

[Slartibart]

what ssd model? casing? Mac model? Try using it via a external powered hub.

 

[paieye]

I am afraid that the urgency of achieving a back-up has made it necessary for me to invest in a new Mac-compatible external SSD. But thank you for th suggestions.