How to Locate a Short Circuit on a PCB?

I’ve had to track down shorts on PCBs a few times, and it can definitely be tricky. The first thing I usually do is grab a multimeter in continuity mode and check between the power rails (VCC and GND). If there’s a beep, I know there’s a short somewhere.

From there, I’ll probe around the board, lifting one leg of suspected components (like capacitors or diodes) to see if the short clears. Electrolytic caps are a common culprit.

Another simple method that’s helped me is the finger test or using a drop of isopropyl alcohol. Power the board with a current-limited supply (set low, so nothing burns), and often the shorted component will heat up faster than the rest. You can sometimes feel it with your finger or watch where the alcohol evaporates first.

If the short is stubborn, I’ve also followed the divide and conquer approach—cutting traces or desoldering sections to isolate the faulty area. It’s not always fun, but it narrows things down.

For really tough cases, tools like an LCR meter, thermal camera, or current tracer make life easier, but I’ve managed with just a multimeter and patience most of the time.