G-RAID4TB GEN4 4TB (eSata/ FW800/ USB 2.0) doesn't mount on Mac Os Sierra

G-Technology G-RAID GEN4 4TB (eSata/ FW800/ USB 2.0) EMEA (S/N W609231434) and many of my other, similar G-tech disks do not mount anymore. Disk Utility doesn’t recognize these disks either.
I am quiet desperate. My operating system is Mac Os Sierra 10.12.6.

By the way- not any of the serial numbers I filled in on the “support case” of the G-tech helpdesk were accepted. Not even the S/N of my most recent, very expensive Thunderbolt disk. It took me more than an hour to fill in the form, without results. Consequently I went to the forums.

Please help me!

The G-Tech support cases don’t require the serial # to be filled in. We have no registration, that is only the WD side.

Have you tried your drives via USB or are you using FW800? For a G-RAID make sure your power adapter is 12v 4a.

Dear Rydia,

That (12v 4a) did the trick. Thanks so much, Rydia!

Cheers, David.