Tried to erect 1589 and the jib would not raise. Checked hydraulic pump, and it was building pressure, but the coil to open the valve bank was not being activated.
Contactor was switching to open, but the control relay for the valve was bad.
Light would turn on the face of the relay, but would not actually switch. The orange screw could be turned to manually make the switch and the jib would go up. Replace relay.