I have done some research about this before hand(https://www.electronics-notes.com/articles/electronic_components/transistor/choosing-replacements-transistors.php). I have a switching 12v dc power supply that had been running perfectly fine for several months until it failed during a rather hot day. The power supply is passively cooled(although it will be actively cooled after I reassemble everything). Once the failure occurred, I tested the components, no bad shorted or bulged capacitors. Only failure was two e13007-2 npn transistors on the input side of the circuit(most likely heat related, as through my research that is their most common cause of failure). Replacing is not physically difficult, and with active cooling I probably could replace them with the same transistor but I am having a hard time finding it available for delivery anytime in the near future.
Since I am not too familiar with npn and pnp transistors, I am asking; would the similar, more available, 13009 npn transistor be an acceptable replacement for the e13007-2 transistor?