Earl
Basically the hydraulic actuators for the primary flight control surfaces are signalled electronically from the flight deck controls, with the degree of computer input/ moderating that takes place dependant on the level at which the FBW is operating at ( normal >secondary>direct). However just in case of a total electrical failure Boeing did indeed provide a manual back up in the form of good old fashioned cables to the stab and selected spoilers...according to the FCOM:
"Mechanical Backup
In the unlikely event of a complete electrical system shut–down, cables from the flight deck to the stabilizer and selected spoilers allow the pilot to fly straight and level until the electrical system is restarted."
Last edited by wiggy; 27th Mar 2014 at 10:23.