Hi all, I have 4 Schindler 5500 units, 12 floors on my route, the only breakdowns I get come up with 1680, preceded by 709 error, easy reset but I want a more permanent solution, can be any floor, any time? Thought it might of been someone bouncing the belts but I have seen it on cctv from inside and nobody was in the car at the time and it’s never a stuck with passengers,Any suggestions?