Get a NEW SD card and RE-FLASH THE software
I have a Titan myself...unsure if Neptunes use the mini-SD cards or not but I use Sandisk brand 8gb Class 10 (you want class 10 imho)
see if that does the trip a power surge can muck up the SD happened on my Titan ..I also always have a spare on hand for a quick swap out for this reason
etc
all that comes to mind now let us know how it works
Thanks for your reply, Neptunes have a miniSD card slot.
Will pick a new good miniSD (bcs tried to use the one from my phone - 1GB noname and the soft replacement didn't started) reinstall the soft and report back.