While testing a new circuit on a breadboard, my good old Arduino Uno suddenly released its “magic smoke” with a loud pop and stopped working. On a closer inspection, I saw that a small crater had appeared on the 5 volt voltage regulator. The next step was to figure out just how bad things were. I powered up the board via the 5v pin from a regulated power supply and…the Arduino came back to life! It looked like the voltage regulator was the only damaged component.
According to the Arduino documentation, the Uno uses a 5-volt linear voltage regulator in a TO223 SMD package. Apparently, compatible voltage regulators are available on eBay for less a dollar for a 10 pack! All you need is patience, for the package to arrive from China…
Removing the burnt voltage regulator, without damaging the other components on the Arduino is a bit tricky, but can be done with some patience and basic tools like thin copper wire, a soldering iron and needle nose pliers using this nifty trick. Once the damaged regulator is removed and the excess solder is cleaned from the pads, soldering the new one in its place is much easier. I managed to take a few half-decent photos while going through the process. End result: Success! The Arduno Uno came back to life with the new regulator and has been working fine over the last couple of weeks!