Charles & Sandra Cohen
The gold-plated contacts on the "separation cable" (and their mates on the main body, and the control head) are _very_ sensitive to dirt.
. . . Clean them well (rubbing alcohol worked for me) and re-assemble.
I had to do that every few months, with an IC-706 on my boat.
Corrosion on the fuses and fuse holders is also common.
. CHarles VA7CPC