(works on a C510 and C710 - C310 can't say)
This method should make it possible to, even after a hard reset, just start up iGO by the MIOMAP pictogram (main menu MioC710)
You need a iGO program for this. I suppose you have it ready on your PC.
If someone tries this with Primo, let us know. I suppose it should work as well.
Step 1
See you have a back up of your ...