[William Sommerwerck]

Needless to say, I have to repair the speaker connections here,
BUT HERE IS MY QUESTION: Why is there no output even
through the eadphones jack? Is the headphone signal routed
through the speaker terminal PC board in some way?

Few -- if any -- amplifiers have dedicated headphone circuitry. The simplest
and cheapest method is to drive them from the amplifier's speaker output,
through resistors to avoid over-driving them. Clearly, the board break is
prior to the headphone jack.

Good luck on your repairs.