Sorry for late response, it probably is because I expected a faster reply. I was hovering this topic and when no response available in 2 days, I just skipped it and looked further. I think I was too much impatient : my apoligies for that. I can't provide any device serialnr, since I received a dismantled device, consisting 2 boards connected at eachother. The USB-part / board contains a crack and the Cypress IC shows some damage too (small hole), right above the connections to the USB-data-lines.
It is partly because of this, that I have the impression that it is not eligible for repair under warranty or whatsoever. I think the only option left is to replace this USB board, which is the reason for my question.