Please help.

Nav was functional when car was purchased, but after wife left key in pos 1, the battery died and the nav hasn't worked since.

I still have full functionality of the OBC including altitude and GPS coordinates, but the map no longer pulls up and I receive a perpetual "please wait..." message when trying to access the map.

I had an independent dealer look at it and he hooked up an OBDII reader but was unable to fix the issue. He said he had never seen anything like the problems that I had with my unit. An oddity that was noticed was that the small Nav symbol in the upper right is only partially visible as it is half off the screen.

I thought that perhaps updating the firmware would fix the problem, but unfortunately, I have had no luck through this process.

Unit is MKIV with 4-1/12 software.

I tried updating with the IMAGE.CCD file but the unit rejected that as unrecognizable. Subsequently tried to update to firmware KrisL V-29 but nothing happens when inserting the CD into the DVD drive.

I have seen recommendations to update to an older software version, but all the links that i have tried seem to be dead.

If anyone has any suggestions or advise I would greatly appreciate the support. I did use the search function first but was unable to locate the specific information necessary to remedy my issue.

Thanks in advance for your assistance