The ac line relay cycles for 500mS, without display indications.
This with or without main TX connected.
Housekeeper is live and rises to 13V during the start-up
attempt. Power detect line ok.

Anyone familiar with start-up sequence of this thing?

Looks like you've got to disassemble the whole thing to get
at the processor/control area.

Is it safe to bypass relay, to run up the power gradually?

RL