mouse23

Like so many others on this forum My screen spontaneously started reading "cannot read disc" or something like that.
Here's what I did so far:

1: Other threats talked about the motors in the DVD nav box. So I took the cover of my nav box, plugged it back in, I could insert and remove the disk so that motor is working; with the cover off I could see the disk spinning, so that motor was good also.

2. I also read about the laser being bad, so I unplugged it again and cleaned the laser. If you don't know how, check youtube.

3 Disc could be bad: I the disk inserted in my computer and could see all the folders on the disk. So disk is OK too.

4 Then I started playing with the screen, touching it in the corners in various sequences, looking for a secret back door to a possible reset function. And this is what I found:

After pressing the hard "Display" button a screen appears to adjus brightness and contrast. But in the center of the screen is a smaller screen with part of the previous error message.
On that little screen touch the corner in this sequence: Top L- Bot L-Top L-Bot L- Top L- Bot L.
And a diagnostic menu will appear.
For some reason this is the second page of another menu, so by touching "Menu" on this menu it will go back to the first menu and I will list all the choices ;

Diagnostic Menu:
System Check Menu
Display Check (Menu)
Navigation Check
[/COLOR]
From the "System Check" Menu:
LAN MON:
CODE CLEAR
MEM CLEAR
RECHECK
MENU (to go back)
On the top part of this screen one will see the check results after about 30 sec.
MEM CLEAR did not respond (luckily); CODE CLEAR did not respond.

From the DISPLAY CHECK MENU:
Color check
Touch sw check
Touch point check
Veh Sig check.

From the NAVIGATION CHECK: This virtual button did not respond.


It could not respond I think, because in the system check menu it already said; NAVI LAN NCON
which means not connected I guess.

Further postulations: LAN usually stands for local area network. In the field where I worked we called it the can bus (controller area network) which has the advantage of connecting each peripheral device with the same communication wire, and each device will listen to specific hexadecimal codes and does not respond unless it recognizes the code. If a device does not respond, like my Navi for instance we would either substitute it or bypass it. Bypassing was done with a special termination plug on the side of the device in question. That would tell us the line was good. In my car I would guess that the line is probably good so the response from the nuvi box is dead (ecu inside the nuvi box), even though the dvd and the GPS inside are still working.
Any GEEKS out there who know how to fix it, or have idea's?

Philosophical questions:
Why couldn't they just make a nav box without the ecu part ( Like a Garmin for instance)
You only need the ECU for diagnostics, and when it fails you need to replace it anyway, even when the GPS is still working, duh!
Since all nuviboxes in all cars are mad by Denso, why doesn't the anti trust law apply to them like it did with Microsoft.
If they are so mass produced, why are they more expensive than a good laptop,?
Isn't a restriction of spare parts to third parties "Restriction Of Trade" which was the case against GE and Philips in the medical equipment field?
Any hungry lawyers out there??

GreeneNC