By the way, if I flash different firmwares on my 3790T (including the 34xx firmware), I am not corrupting or changing any unique device information contained on the NVRAM of my device, right?
By flashing non-standard firmwares you can corrupt some important NV records which would make the original firmware crash on some conditions. In order to repair it you will probably have to erase your NV, thus loosing your device's model number (3760, 3790), restoring which is quite cumbersome So, make an NV backup before you start doing anything. It's a useful skill in any case.
It depends on what you do: flashing different firmwares is risky and if something goes wrong you can brick it or you can have some loss . For example model number or unit ID loss. NV backup preserves to trash your bricked unit or to ask for help to revive it (if possible)
I think if you flash something different in Nuvi from what is standard, you must have a bit of knowledge about what are you going to do. If you have it ,you surely backup your Nuvi NV
Uh kunix was faster lol
For example, I remember that after flashing some asian firmware on nuvi 13xx/14xx european firmware started crashing when entering some menu because the asian firmware has written a wrong selected menu item number to some NV record because it used that particular record for a different purpose.
But such problems usually are solved by pressing "clear nonvol". The real problem comes if your device doesn't boot at all. Then you would have to erase NV with "ergn,41" (and loose your model number) or restore it from a backup with "xrgn,41" (and loose nothing).
So I would suggest you "clear nonvol" and make a backup now.
Yes, "clear nonvol" erases a lot of info, including all your settings. But you don't loose anything which can't be restored when performing "clear nonvol".
Last edited by kunix; 30th March 2013 at 01:42 PM.
Yes. Also "clear nonvol" is frequently needed when flashing non-standard firmwares (two times: before flashing and after flashing) and when returning to original firmware (two times also).