Thanks, i'll have a look.

The Nav Screen only works when the lights are on (either sidelight or dipped) regardless of ignition position. There is no sound or picture until then - it does flicker though but buttons remain useless until the lights are switched on.

My only thoughts with water are that this only started happening this week - just as we started getting torrential rain and flooding. That said, i've not driven through stupidly deep water or anything. Maybe coincidence.

Thanks for your help.