What type of routerboard are you using? If it has a serial port you can connect to it
through this port.
Have you tried to connect using mac-address with winbox, instead of IP address?
Pc, also has a serial port, will work with telnet, read manual on howto. You can use mac instead if ip to connect onto mikrotik with winbox, on Ethernet port.
Assign ip to bridge, normally bridge take Ethernet port ip automatic, but better to assign. Only assign bridge the ip, not any of the ports using bridge, like your Ethernet port.