the serial number can be found on the bottom sticker on the original packaging. it's displayed in the format of X3C-#####.
it can also be found behind the backplate in the bottom left corner.
the third and final way to retrieve the OP-Z is to:
- start the unit in upgrade mode.
- OP-Z will show up in the computer as an external removable usb disk. open it.
- open the folder "systemfolder"
- open the text file "serial.txt"
- your OP-Z serial number will be displayed in the first line, next to "unit: "