Why has neon stopped working?

Could you elaborate on why the neon has ceased functioning? Have there been any recent changes in the system or the environment where the neon is located? Is there any visible damage or abnormality in the neon's appearance? Are there any error messages or indicators that might provide clues to the cause of the malfunction? Additionally, have you checked the power supply and the electrical connections to ensure they are properly functioning? It would be helpful to have more information in order to accurately diagnose the issue and find a solution.