What causes a sequencer to fail?

Could you elaborate on the various factors that might contribute to a sequencer's failure? Are there specific hardware or software issues that are commonly encountered? How does the maintenance and upkeep of the sequencer play a role in its reliability? Additionally, are there any external factors, such as power outages or network disruptions, that could potentially lead to a sequencer malfunctioning? Understanding these factors would be crucial in diagnosing and preventing future sequencer failures.