Simplex 4002 “system trouble”

Hope to get some help!
I performed a fire alarm inspection on a Simplex 4002 panel. The test went fine, every alarm came in and cleared. At the very end there was the LED lit up next to system trouble. I checked the signal circuits wires which were reconnected and tight. All the switches were back in normal position (down). No zones were in trouble or alarm. The system trouble led was the only one illuminated. Any recommendations or help?

Was the panel in WalkTest during the inspection? On a 4002 a reset must be followed by any DIP switch change for it to take effect. When in WalkTest mode, the system trouble LED will be illuminated. Make sure WalkTest is set to off (DIP switch SW2-1 is ON) then press reset. See if the LED goes out.

I disconnected the signal circuit wire (for the horn strobes) but did not touch the dip switches.

Was the panel normal when you got there? Was anyone else involved in the inspection? It’s possible the panel got left in walktest, I’d start with double checking the DIP switches and doing a reset if you can.

It was just myself doing the inspection. The panel was normal upon arrival. I will double check the dip switches to make sure it is not in walktest and on another note or could be the issue. The monitoring company only received one fire signal and no restore. The city trouble light is not on, the cell dialer has good signal strength. And like I said the only trouble led on is the system trouble. Thanks for your help!

Check batteries. Try replacing & power cycling facp if you haven’t done so. Next assumption would be a power supply issue which sucks for an end of life panel. The active trouble may be holding off an aux connection to your cell dialer thus the reason for no restorals.