Just took over job no print 4 car group.Cars keep going on fire return to main landing about 4 or 5 times a day.So we replaced all smokes an problem went away for month or so.Other company put voltage monitor on 110 circuit.Have checked key switch in hall station everything tight an reads good latching smokes an no smoke detector active.Also no service tool yet getting one.My thought is maybe a power supply in controller or cross connect but don't know would each cars power supply take over when one car shut off.Hope I explained this enough.

Had one awhile ago that would go on earthquake every so often. A duplex system...Only one car would set earthquake. Turned out to be an older unit that was a freight elevator with MG set on same power source would lower power on others at start up... And trigger earthquake....

If you suspect smoke sensor power blips try a Battery Backed UPS Supply to power the sensors. Building should pay for that. Unit may react on a blip but no error registers. It happens so fast and restores, the error did not detect in the program loop.