I am terribly sorry that I do not have any other ideas. Maybe the board is damaged.
Check if you do not have protected boot options set.
@mrz: Although I have never used this feature (it’s not needed in home environment anyway), is in my case any way to check this?
From docs:
Unsetting of this option is only possible from RouterOS. If you forget the RouterOS password, the only option is to perform a complete reformat of both NAND and RAM with the following method, but you have to know the reset button hold time in seconds.
@AndreasGR: Thank you for you ideas, I appreciate it.
Does this issue have any solution?
Why Mikrotik accepts corrupt or incompatible backup files for restore?
How can I check if a backup is safe to restore?
@normis, why RouterOS accepts corrupt or incompatible backup files for restore?
Thanks in advance
BUMP @normis / @mikrotikstuff
Thanks.