I'm afraid that I'm out of options and I can consider this device as "bricked". Well, the last resort is to reinstall device firmware but on Mio devices this is hard labor as you need to disassembly the unit and bridge the pins on the chip so you can get into recovery mode. But first you need to have correct ROM for this Mio and I have no clue where to get it. I did it once on Mio Moov M400 but it was a quite a project and I got the firmware from the site which is now long gone..