While using a digital multimeter to diagnose electrical problems on customers’ equipment, I frequently hear the comment, “I’ve got one of those multimeter things, but I never learned how to use it.” ...

Welcome back to our Tech Tip series! Today, we’ll review one of the most essential tools in every toolbox, a multimeter.

Q: A friend tried to change three-way switches for me at the top and bottom of my steps, and now they don’t work right. Then, all of a sudden, my doorbell stopped working. A friend at work said I ...