If a circuit has no output voltage, what is a good first step to troubleshoot?

When a circuit shows no output voltage, checking the input with a voltmeter is an effective first step in troubleshooting. This approach allows you to confirm whether the circuit is receiving the necessary voltage to operate correctly. Ensuring that the input voltage is present helps narrow down the potential issues; if the input is absent, you know to focus on upstream components or power supply problems.

This proactive measure avoids unnecessary component replacement or circuit disassembly before verifying that the basic requirements for operation are met. It also helps in isolating issues quickly, allowing for a more efficient troubleshooting process. By confirming the input voltage first, you can determine whether the problem lies within the input supply or if it is downstream in the circuit.