WD Elements 2620 appears in Eject, but gets no disk letter and is not shown in My PC

I’ve been using this external drive for months, downloading and copying movies to it and playing them. Everything worked fine, until a couple of weeks ago. The device is no longer appearing in my PC, so the content ( about 3.40 TB that I don’t want to loose) is no more accessible. I tried using another USB port, even another PC, nothing works. The drive appears as Elements 2620 to eject safely, but without drive letter. I hear the drive humming softly when connected and the little light is on, but nothing more happens.

Hi,

You could refer to the following link: Error