He diagnosed my problem of lost navigation perfectly. I switched HDD drives and the navigation came back without updating the operating system which was 1.908.
I then updated to 2.120 by DVD. Tried to do it with USB, but was unable to get the unit to read the update file. It would read a music file but not the update. Tried with a different USB, but it didn't work either. That's when I went to the DVD and it worked perfectly. Took about an hour and twenty minutes to update.
After the update I checked a few things and all seemed to function OK. Will check out other details as time permits. I took a few pictures to help document the process.
Thanks all for your input and especially Marco for his help. I really appreciate it.
2011 Overland Summit, Hemi, 4x4, Mineral Grey