This guide covers how to set your multimeter to diode test mode, read forward-bias and reverse-bias values, tell a good diode from an open or shorted one, test in-circuit versus out-of-circuit, and handle specific types: rectifier, Schottky, Zener, LED, and bridge. This guide covers how to set your multimeter to diode test mode, read forward-bias and reverse-bias values, tell a good diode from an open or shorted one, test in-circuit versus out-of-circuit, and handle specific types: rectifier, Schottky, Zener, LED, and bridge. Knowing how to test a diode is one of the fastest ways to troubleshoot a faulty power supply, malfunctioning circuit, or PCB that won't power on. Using a digital multimeter, you can quickly determine whether a diode is working properly, shorted, or open. This guide covers how to set your multimeter. Whether you're troubleshooting a power supply, repairing a circuit board, or just verifying components from a batch order, a multimeter's diode test mode gives you quick, reliable answers in seconds. In this guide, we'll walk you through how to test a diode with a multimeter, covering standard. Digital multimeters can test diodes using one of two methods: Diode Test mode: almost always the best approach. This straightforward process helps diagnose issues quickly and effectively, saving.