Download the winbox tool from the MT website: http://www.mikrotik.com/download/winbox.exe
install it and press the ´neighbourhood´ button (right beside the “Connect To:” field, left of the ´connect´ button)
If your PC is dhcp-client wait until the message comes up no IP is being received and the default one is set.
Or set a manual IP not in the expected range of the routerboard.
Now, by pressing the said button in the flap-down list the mac address (+ IP if available) should appear.
Click on the mac address and login with default admin and password (“admin”, no password) or the ones set and you have a mac-winbox session with the same functionality as a full IP winbox session.
Now you can manage the routerboard and check if their is an IP available on the ports you attached to.
That would also be my guess. I router is not coming up, not even with mac. in the winbox discovery tool, that usually means something serious is wrong.