This is the comment I use when calling out a FPE panel.
The main electrical distribution panel is a Federal Pacific Electric FPE panel. These panels have a reputation for being problematic and further evaluation by a qualified electrician is recommended. FPE panel breakers are known to fail to trip at a much higher rate than standard panels. When a breaker fails to trip, the breaker and other components, including wires, may overheat and melt. The panel itself could overheat and catch fire. A qualified contractor should evaluate and replace as necessary.
I have observed a Federal Pacific Electric “Stab-Lok” service panel in the house.
This panel is a latent fire hazard: it’s circuit breakers may fail to trip in response to an over current or a short circuit. Failure of a circuit breaker to trip can result in a fire, property damage, or personal injury. A circuit breaker that may not trip does not afford the protection that is intended and required.
Simply replacing the circuit breakers is not a reliable repair. The panel should be replaced, and significant expense may be involved.