I've searched around the forum and found a lot of good info, but nothing exactly fitting to what I need.
I just bought an R34 that originally came with a Xanavi HU. But the dealer removed only the HU before selling it to me saying that it was already broken, and replaced it with a tray, essentially making it a cassette only vehicle. The screen is still there but not connected. Afterwards I bought a used Xanavi HU and put it in its spot, and all it does is beep. Goes like this: "beep.........beep beep". It does it every 10 mins or so. Seems like a error code. It does allow me to eject and insert a disc (upon which it does the beep sequence again). No other buttons do anything, and the screen never pops up. Also it lights up with the instrument cluster, but that is it.
Was I lucky enough to have two bricked HUs consecutively? Any ideas?
Also does anyone know what that one socket is, on the extreme right side on the rear of the HU? It is sort of copper, round and almost coaxial, and doesn't seem to have anything to plug into it. Some people's pics on the forums also show nothing plugging into it. I plugged in everything into the HU, except for whatever goes in this thing.