[sdiy] power supply explorations

[Mountain Man]

My voyage into the Xpander power supply has begun!   I got a batch of
electrolytic caps today - when I opened the unit a couple of weeks ago I
noticed that a couple of the caps were punctured.  I had hoped this was
the problem.  Replacing all the caps made the board look better, but
that's about it.  I noticed that the transformer on the board is getting
quite hot, and sort of looks like it's been doubling as a marshmallow
(that lovely toasty brown color).  Does the transformer getting very hot
mean that it has a problem, or might it be a component up or downstream
of it?  If it is the transformer, I need to find out how to get a
replacement.  The transformer has on it "661023"  and  "51420"   I don't
see any other identifying marks.  In the service manual there's a part
labeled  "power xfmr 30 Khz 8103-T1 incon"   I'm guessing that's it, by
elimination (there is another very large off-board transformer; there's
only one transformer on the parts list, and I'm guessing it's the
on-board one)  Can someone decode this for me, and point me to the right
transformer to order?

Thanks much,
Elby