If converter was smoking then it needs replaced because things melted in it, hence the smoke. Could be just a faulty converter (how old is converter). I had a similar case and just the converter was bad. You can disconnect converter from all rv circuits and test it by just feeding shore power to it and see if it is converting to 12 volts and does not smoke at same time. If all is good, hook up each circuit from rv until smoke comes back or breaker trips. That circuit will be the one with short in it.
Before you hook up a new converter, you need to make sure there are no shorts in the rv circuits both 12 volt side and 120 volt side.
If no breakers were tripped then I would suspect and test the converter first.