Quote Originally Posted by wojtech View Post
If I go through setup on the unit and go to the select map page the screen just goes blue, if I press Enter the unit turns itself off.
You made something wrong flashing it, I suggest to hard reset it and reload the software- Be sure your batteries are charged.
Remove any gupdate .gcd from your unit or sd, open your Garmindevice.xml and change in it your software version to a previous one, save it. Plug your 78 to your pc USB and use Webupdater to reflash it. Wait till your unit has completely loaded the firmware and restart itself. Hard reset it again.