>If it's an unregulated wart (most are) running under stated load may
>be as much as 16-18 volts.  70C seems very hot to me.

That wasn't clear.  I mean a supply running significantly below its rated load.

>read the bands, looks like black brown?/green? black black in the
>photo.  Black green black would suggest 50R

And that's just wrong.  Black green black would suggest five ohms,
not fifty; and it would be green black gold in that case anyway, not
black green black.  No resistor code in US usage (EIA code) starts
with a black band.  I should do this when I'm awake, or twenty years ago.  ;-)

The EIA code is here:
https://en.wikipedia.org/wiki/Electronic_color_code#Resistor_color-coding

Yrs,
d