Background: Electronics novice, attempting stereo amplifier repair for educational purposes. Amp (Pioneer VSX-519V) blew when the input was removed while at high volume. Careful visual inspection does not sight any damaged components.
Am in the process of learning how to check a transformer. The first two wires (black/blue) on primary have continuity, 1.7ohms, and 110v AC is present to the terminals that supply power to the transformer. There is no voltage present on any of the output terminals.
There is a second set of thick wires from primary coil: three wires (yellow-red-yellow) that have also proper continuity, but no voltage.
The secondary coils have two groups of three wires, and one group of six wires. Each group has continuity, and expected resistance's, but there is no voltage (AC) present anywhere.
There is no continuity between primary and secondary windings.
Question: based on the above, does this transformer have a problem? I do not presently understand why all the other readings look good, but I have no AC voltage on any secondary windings.
When the transformer is taken out and tested on the bench, it is fine. (that was a good lesson). When the transformer is installed, something else is "tripping" and cutting power to the transformers primary coil during startup.