A damaged dilithium crysal circuit.
The dilithium crystal circuit was a vital component at the heart of the dilithium crystal converter assembly aboard Template:ShipClass starships.
In 2268, while attempting to use their deflector to alter the course of a large asteroid, the Starship Enterprise's dilithium crystal circuit burned out due to the enormous amount of power being drawn. (TOS: "The Paradise Syndrome", "Elaan of Troyius")