Horizontal lines?

[mfk]

This is normal and is due to the nature of the technology.
However, some devices do indeed have problems.
See:

Screen issues. Dark lines gradient

Finally got my Digitakt II back after sending back to Thomann. They paid for shipping and repair was covered, by warranty although was a bit of a pain to avoid paying duties on it again upon return. 5 weeks from when I shipped it back to them, and back to Cape Town. Super impressed!