There is no software update for that unit but if you are having issues like that have you checked the voltage? If its dropping voltage then it wont boot up properly or at all. Try checking the voltage at the machine to see if its getting 12v or more. If good voltage and still having issues you can send it into our repair center for us to check out!
Please make sure to include your contact information and what's going on with the unit. The address is listed below for your convenience.
FurunoUSA
Attn:Service
4400 NW Pacific Rim Blvd.
Camas, WA 98607-9408
There is a $135 evaluation fee. They will test it and see what's going on with the unit!