Do not worry. When you are asked for your password it is normal for you to see nothing in the Terminal. You only see black blobs when typing your password outside Terminal.
Just type your password on your keyboard and press Enter.
The dpkg configure command should do as requested.
One additional tip: if you are using Synaptic package manager anytime and a Broken Package notice is shown (even after you have tried using dpkg configure in Terminal to repair it) do this:
In Synaptic click on Edit, select Fix Broken Package(s), then click on Apply, Apply.