I have an Avic N1 and seems like it works only when it feels it wants to. If I leave the faceplate on the in-dash unit when I turn the car off, then when I turn the car back on the unit powers on and off consistently until I remove the faceplate and connect it back on.
So I hear the disc (or fan) turn on and the lights illuminate for about a second, then turn off for a second, then back on again, and back off consistently until I remove the faceplate completely. If I remove the faceplate completely, I can hear the unit is still on (either the navi disc is spinning, or a fan is spinning inside the unit, whatever the normal sound for when the unit is on). Then when I connect the face plate, sometimes it will shut off and back on repeatedly as before, and sometimes it will power up normally like it's supposed to.
I know this probably sounds really confusing, and if someone needs a video or something of what I'm talking about, I can try and get one. If anyone can tell me what in the world is going on with my unit. My N1 is about 3 years old.