Cann't SSh to Nanopi Core 2

[nnmmss]

we have a few Nanopi core 2 which all of them are installed. the person in charged has left the company, Now we want to SSH to them and they reject it. I used to the nmap command to view the status of port 22 , they show that port 22 are filtered. how can we access the nanopi?

[Werner]

Put a serial console to it and use that if you know the login credentials. If you do not know you have to physically remove the sdcard and mount it on an existing Linux system to modify the credentials.