Updating this Blog subject,…
IC-781 HF transceiver now working fine (fingers crossed) so we’re back to 3x HF radios in the shack.
Insidious R20 fusible resistor kept tricking us into thinking there was a downstream failure embedded in the power line supply.
Turns out that Icom engineers very cleverly designed this inline resistor just below the edge of it’s power handling capacity.