Which device would you use if you need to check circuit problems without power?

To check circuit problems without power, an ohmmeter is the most appropriate choice because it is specifically designed to measure resistance in a circuit. When the power is off, the ohmmeter can determine if there are open circuits (breaks in the path) or short circuits (unintended connections that bypass the intended path) by sending a small and manageable current through the circuit and measuring how much resistance it encounters.

In contrast, a voltmeter requires power to measure the voltage across components and is ineffective when the circuit is de-energized. An ammeter, which measures current flow, also requires the circuit to be powered for it to function properly, as it needs to detect the flow of electrons. A multimeter, while versatile and capable of measuring various electrical properties (voltage, current, and resistance), includes ohmmeter functionality; however, the most focused answer for checking circuit problems specifically without power is the ohmmeter.