Aporte original por: Richard ,
You may have a short in your secondary winding. A short will still register as continuity, but the output side of the transformer will be effectively non-functional since it will be unable to convert the magnetic field from the primary winding into electric current. Unfortunately these can be difficult to troubleshoot. You may be able to find some information with a web search, but it tends to get into sensitive measurement, and honestly unless you're willing to re-wind the transformer coils you're probably going to spend a lot of time (and maybe money) for little gain.