Sure thing! When dealing with a Simplex 4100-6120, the first step is to check the display for any error messages or indications of trouble. From there, I’d recommend checking the wiring connections to ensure they are secure and intact. Sometimes faults can occur due to loose connections or damaged wiring. If everything looks good there, it’s a good idea to check the power supply and battery backup to make sure they are functioning properly. Additionally, you may want to review the event history to see if there were any recent events that could be contributing to the issue. If the problem persists, it may be necessary to contact a certified technician for further assistance.