fdiaconu
It looks like there is something else broken in your nuvi except the filesystem of the internal flash drive.
That white screen may indicate something bad.
The fact that your device gives an error while trying to run boot.bin ("System Software Missing", first stage) is definitely a bad sign.
My cure isn't designed to deal with anything except currupt internal filesystem.
But we can still try to do something.
Try flashing two RGNs from this archive [Only registered and activated users can see links. Click Here To Register...] and tell me what happens.
Only one of them is suitable for your device as there are two different devices called nuvi 13xx.
Then tell me the name of RGN that was suitable. So I will know your nuvi's HWID.
P.S.
I've just discovered that nuvi 13xx is able to flash RGNs with no boot.bin inside. That means that the bootloader is able to flash regions. For two years I was sure it's impossible. Life is a wonderful thing.