OK Pete - hang in there and maybe we can get it going for ya.
I am not sure what you mean by "umbilical cord". I'm guessing that is
the remote head cable that connects to the radio chasis? Is that right?
Did this radio ever work ok for you since you received it or did this problem
start recently?
Do you have any local ham friends with any test gear that may be able to help?
Since its happening on both bands I'm gonna say its probably either an attenuator
that's been activated or the rig needs to be checked out thoroughly with test gear.
Also - perhaps you do have it accidently set to receive in digital voice mode when
you are trying to use it for analog fm.
I have the Icom IC-D800H and only use the software/pc to program it as its a real
PITA trying to program it via the control head or mic controls.
Keep me posted and good luck.
PS - I do have relatives over in England across the great pond and would
love to visit some day.