Which component is essential for troubleshooting controller problems?

Multimeters are essential tools for troubleshooting controller problems because they can measure various electrical parameters such as voltage, current, and resistance. This capability allows technicians to diagnose issues within circuits and confirm whether components are functioning correctly. For example, if a controller is malfunctioning, a multimeter can be used to check the voltage supplied to the controller, the continuity of connections, or the current flowing through specific components.

In contrast, while circuit breakers protect circuits from overloads, they do not aid in diagnosing existing problems. Capacitance meters specialize in measuring the capacitance of capacitors and are not versatile enough for broad troubleshooting tasks. Frequency analyzers are useful for measuring frequency and waveform characteristics but are not as crucial for everyday troubleshooting of controller issues as a multimeter. Therefore, the versatility and comprehensive measurement capabilities of multimeters make them the primary tool for identifying and resolving controller problems.