Common Faults in Linear Transformer
Primary winding open- This could be a result of a power surge but could also be a short on the output leading to over heating. Since the primary winding is open, the transformer would not work at all. You may use a resistance test to confirm if the winding is open circuit.
Shorted winding in primary or secondary- This may be the result of over heating or be just due to poor manufacturing. A shorted winding will usually blow the main fuse. To accurately test if the transformer have any shorted winding, you have to use a ringer tester.
Shorted between the primary and secondary side- Though it is quite rare but i’ve seen transformer shorted between the primary and secondary side causing the main fuse to blow.