Mariner 90 hp outboard hydraulic tilt?

The hydraulic tilt on my Mariner 90 hp engine suddenly stopped working. I checked the power and there is voltage appearing across the leads to the hydraulic pump when the button is pressed for up or down operation and the relays click whenever it is pressed but there is no response. I figured out how to put it in the manual mode by turning the screw counterclockwise but I haven't been able to make it operate again in automatic mode. I didn't find any limit switch that might not be acting correctly and I've run out of ideas. Do you have any?