I am working on fixing an old bullhorn and I'm not sure what is wrong with the unit, so I am going to replace all the Capacitors and transistors in the unit.
but I am having a hard time finding the proper transistors.
here is what is printed on the transistors.
-9012 5d g e c b
-1702mph53
-c945 q14xc
I am looking to get an exact replacement but I am not too familiar with what is interchangeable.
Blindly replacing components isn't a good way to try and repair something, and you're as likely to cause as problems as you might cure.
You need to fault find, and see what's wrong - first job is to locate a circuit for it, or draw it out is one isn't available (as seems likely) - there isn't a lot in a bull horn, so it should be easy enough to draw out.
FWIW...@OP.....semiconductor junctions rarely "wear out". It does happen when a junction goes open....ive seen it here a few times with 1N400 series diodes in the Frame Stage of CRT. But its rare. Junctions normally fail completely...so...just changing transistors etc will not solve your problem...unless you find a leaky or shorted transitor/diode junction. Other that nope.