We lose the second floor down button first. Then a week later we lose everything. We have changed the button on that floor, same problem.
Does the lift have a loom that runs down the shaft then the landing button module connects to that for the button panel? Does the loom from the main line down the shaft plug in or hard wired? If it plugs in, swap it for another level and see if the failure follows the change. Or if it is hard wired, replace the button loom with a new temporary loom(before an after button module if required) and disconnect the existing loom and see how that goes. Also check all the insulation around that landing panel, to make sure no shorts are occurring.
