Exist a risc to write to ROM (eMMC) of the BBB Board?

Hallo all,

I’m new in the group.

What are the conditions to write Data to the ROM (emmc)? If I store data at a file, will this data write in time to the ROM or exist a local RAM and data will write to ROM by shut down or if a sector is full to write.

Which risc exist if the BBB board lost power supply without correct shut down? Can the Hardware damaged? Only lost of data? Only tile System damaged?

I had two BBB Boards, the first can’t flashed new Software after a false shut down (emmc fault) and the second doesn’t starts (POWER LED is off).

Can someone give me a Hand?

Best regards