I have a 2000 telsta a28d. boom will not move at all. tested controls from ground panel. getting 12.8 v in main control box in truck bed when ground control buttons are pushed. Also tested all of the solenoids. Getting 12.8v to each of the solenoids when buttons are pushed. The truck is a 2000 k3500 chevy that the telsta a28d is mounted on. Any ideas that could help me. I have no diagrams for this piece of equipment.