What you expect to see across the power cord spades, with the power switch On, is the power transformer primary winding.
There should be no connection to ground whatsoever. (from the spades)
What readings do you get?
If there is not a mains connection to ground, that leaves the transformer.
At that point, disconnect the secondary windings & try again.
Worse case, the power transformer alone is blowing fuses.
In that case, it's time for a new tranny.