On Fri, 29 Nov 2019 09:10:20 -0800 (PST), wrote:

As you have a working board how warm/hot does the transformer on
that
one run?

50Hz transformers normally run no more than hand warm. To turn anything
black it must have been well overloaded.

Or hand warm for a long time, like 12 years...

--
Cheers
Dave.