We had this discussion a while back and I warned you to check the 2-wire Compatibility document from Simplex to make sure the smoke detector is compatible with the 4004…
<URL url="Wiring a Cerberus Smoke Detector text=“viewtopic.php?f=4&t=6174”>Wiring a Cerberus Smoke Detector
You obviously ignored my warning. I bet the smokes no longer work because the Simplex panel is powering them in a way they were not meant to be powered. Also, don’t the detectors say “MAX VOLTS 9.5” on the back?
However before I jump to conclusions…
- Did you stick a meter on the zone and verify that 24 volts is coming out?
- Did you try the detectors on a different zone?
- Are you sure the detection chambers are not clogged? You mentioned in your other post that you were using Axe.