[Mondial]

If the filament winding has a short, you must replace the power transformer. Even if you disconnect the winding from the tube filaments, it will draw excessive current and cause the transformer to overheat.

Are you sure the transformer filament winding itself is shorted? Have you disconnected it completely and checked the open circuit voltage? It is unusual for the filament winding itself to short. More likely the winding leads where they exit the transformer casing are shorting or something external in the wiring.