[R-390] Broken Line Input Wire in R390?

[Jacques Fortin]

Hi Barry,

You wrote: "the A side of the line input filter is also showing a very high
resistance from the A input to the A output"
I believe that your problem is just there: the inductor in the A side of
FL-101 opened, or the internal solder(s) failed, whatever...
I replaced the whole input filter (FL-101) in my set long ago, because it
was making a GFI tripping and the leakage to GND of internal caps failed all
the tests.
I fitted an IEC 320 male receptacle in it's place that include a line filter
with modern components.
I also done the same with my three R-390As, and for the same reason.
I can send you pictures if you are interested.

The alternate way will be to open your FL-101 and repair it.... 
Just hope it is filled with wax, and not epoxy.
Most probably, the internal inductor on the A side gave up because the
output capacitor within the filter shorted.
I also bet that the live side of the 120V line was connected to the A
side...

73, Jacques, VE2JFE in Montreal