Very hard to say without a schem. My first reservation would be that most printers don't require current. Unless you mean to say that this thing was built to power some kind of mechanical printing machine. In which case we have no idea what kind of signal would come out of the back end. Or what the ideal load would be. You can bet it's nothing like a speaker load. Salvage whatever you can (big heat sinks are expensive) and put it back. Just one suggestion.