Motor transistors keep dying on me

[radardoug]

Have you double checked that there is no connection between the transformer windings that supply the two motors? Your symptoms sound like exactly that fault. Those windings need to be completely separate. If one transistor hangs in there fine, it points to a wrong connection between supplies.

 

[EmilFrid]

@radardoug thanks, I will have a look tomorrow. I hope there's no catastrophe waiting for me