You have wiped out your input voltage circuit. To be brutally sincere you've probably destroyed the board.
That being said, take a look at the schematics -
http://wiki.espressobin.net/tiki-index.php?page=Schematics
select your model ...
scroll down to page 14 and look at U9 - the regulator ... if all you did was wipe that out, you could replace it. You will need hot air soldering equipment and skills.
HOWEVER, it's my experience that when over voltage is applied to a regulator, many times it fails by passing the power rather than blocking it. There is a good chance that 19 volts was applied to many 1.8 and 3.3 v circuits. In that case your board is toast.
Mark it up to expensive education ... we've all done it. Most of us have plugged 12v into 5v boards that have no regulation. In that case the board is also toast.
Francesco Zuliani got a reaction from Werner in Wrong power supply. Board does not start