It works! I got the choose-language screens, warnings, the map, and menus with mostly greyed-out options.
Next is installing it... 
Care to expant a bit? I bought it second-hand but by the looks of the cables this unit was never installed anywhere.
Thanks
Dani
Since it seems it has never been installed, and it isn't bricked, you are probably as safe as anyone. A gadget this complex can have other issues, such as audio quality, reliability, noise, sensitivity/signal loss. There are other problems besides DOA that these things get returned for. If you look thru the Troubleshot section, you will find lots of issues that required replacement.
BTW, just because the cables look good doesn't mean it wasn't installed. The ends can be trimmed, or the harnesses can be replaced with new. But if everything looked "factory fresh", chances are good it wasn't someone else's problem they were unloading.
Do you get any warantee? I bought mine thru a non-authorized seller at a good discount at the time (pre-Z120). The seller warrantee was the same as the factory, but if I had problems, I had no factory warrantee support. So far (6-months), no problems.
Are you installing it yourself? Depending on the vehicle, it's not that tough. I had help from someone experienced with both the car and the HU, and it still took us 6 hrs.