[shorod]

I trust you've confirmed that the belt is turning the power steering pump and the pump pulley is not just spinning on the pump shaft, correct?

I suppose you could try disconnecting the pressure and return lines from the power steering pump and loop them together, then start the engine and see if you get movement of the fluid in the pump. You could also disconnect the lines at the rack and make sure one or both of the lines are not plugged. That would be much easier to do with the lines disconnected from both ends.

-Rod