The answer to 'why is my electrical panel not working' is that there are several common causes, including a tripped circuit breaker, a faulty breaker, loose connections, or an overloaded panel. Symptoms may include lights flickering, outlets not working, or the entire panel being dead.
First, check the circuit breakers in the panel. If a breaker has tripped, simply reset it by switching it fully to the 'off' position and then back to 'on'. If a breaker continues to trip, there may be an issue with that circuit that needs to be addressed by a professional electrician.