Mondeo Blaupunkt NX NAV unit issue

Hi guys, I'm hoping someone can help me. My daily driver is a Mondeo Titanium X Sport 2010 TDCI, and it has the Blaupunkt NX Nav unit. Now I had to take the battery off the car and then when I put it back on the radio wanted the security code, but I knew the touch screen wasn't working, so I couldn't get it back on. Now this unit controlled both the usb socket you have in the glovebox and a 6 disc CD changer in the boot. As I couldn't do anything with it I actually found a second hand one with working screen and code and put that in. 

Although the radio and all the climate control etc etc work it won't play the usb stick, when I press the CD/aux button it comes up with 'line in' and a picture of what I guess is a usb stick and that's it. It also seems to recognise I've got a CD changer attached because it will show me I've got a 6 disc magazine in on the main convers display but doesn't recognise if you put a cd in. It does recognise if you take the magazine out though and tells you 'no magazine'.

ps It does play CDs in the main unit fine. In fact I think the unit only recognises that it's got a single cd, although the convers dash display seems to know there is a changer.

Now I contacted the seller and he said the car this came out of didn't have a cd changer or a usb port, so I just wondered if there was some sort of update you could do to the unit to make it recognise them properly. Or some sort of setting that will sort it out.

If I can't get it working on these bits the only other thought I've had is to take the screen off this unit and put it on the old one, because that did do all the other bits, but I don't want that then to not be compatible and end up with no stereo at all.

I've attached a pic of the type of unit I've got.

Hopefully someone can help.

Thanks 

Trev.