A.6. The console is unresponsive after connecting
The terminal's screen may be blank after connecting to the
   machine.  Pressing Enter will usually bring up a
   login: request.
If no characters appear upon the screen after pressing
   Enter do not panic.  The machine must have power
   and the operating system must have booted: for our call to be
   answered by the modem Data Terminal Ready must be active.
The most likely thing is that the machine booted and is
   running a fsck filesystem check.  These checks
   can take some considerable time, all with no or very little
   output.
It will help your peace of mind considerably to record in the
   system log book the time fsck takes to check
   each filesystem.
If you see garbled text after pressing Enter
   then there are mismatched bit rates or parity parameters.  Correct
   your terminal emulator's configuration.