Just to add a little log to the fire, the 747 classic (and I suspect the -400) is all cable and pulleys from the control column to the hydraulic actuators, but if you lose all hydraulics, which is highly unlikely with 4 systems, you do not have any 'manual' back-up. You cannot move the controls by conventional cable link.
Does that mean it is fly by (cable) wire???
Rgds
CL747