Originally Posted by KiwiJochen

A mono nav cannot display anything on a colour screen

A colour nav cannot display anything on a mono screen

If you have changed the nav from mono to colour, then you need to fit the nav into a car with a colour screen

Using NavCoder you can see if the nav is still "alive" by talking to it (reading nav config, etc)

Originally Posted by adi320

if I insert back the v25 mono software the power light comes back on and display works again, which means my mk3 did not die. Question is if after upgrade to mk3 colour, power light turns off and display as well.. means it has been upgraded? I can do this back and forth.. thanks.