Correct there is a relay driver (Q700) to pull the low side of the relay coil (RL701) to ground. The high side of the coil and the N.O. contact is sourced through the front panel fuse, which checks OK.
No matter what the state of the power switch, POWS never goes low, to turn on the relay driver and therefore RL701. Seems like Icom (in my mind) got the signal names backwards: POWS should be the switch and POWK as in 'K' for the relay, but they are opposite. No big deal, just confusing.
It seems as if the CPU board is brain dead. Tonight I will look at the XTAL pins with a scope to see if the CPU is getting a clock.
Another interesting observation is that there are tiny dots of corrosion, along the top row of pins on the CPU and a spot to the right side of the CPU, extending to a small group of surface mount components. I'll try to clean up those areas better with a fiberglass brush and maybe take some pictures. There are ventilation slots on the CPU board shield that line up with the ventilation slots on the top cover. Brilliant! I don't recall anything splashing on the rig, but for the 5 years it was mounted to the floor as a mobile rig, who knows.
Regards & 73,