I agree that "the keyboards are without a cable" is very awkward in English. But it does show that one knows exactly what the Romanian means. It's what Romanians would call a "motamo" translation (traducere motamo, from the French mot a mot), and they themselves would laugh at it a bit. Still, we can learn from it, and it highlights the difference between Romanian idiom and English language idiom. Good Romanian syntax is sometimes bad English syntax, and that's a real key to idiomatic language learning.
I kind of agree it would be better to use the real translations. In that case would be nice to confirm that Romanian people would actually say "fără cablu" to talk about a wireless device. Or is it just a sentence using the word cablu that we just learned, just like we see sometimes "incorrect forms" being used because we didn't learn the complex ones yet.