No matter what your experience level with troubleshooting, there’s always at least a little apprehension when you have to start poking through a mains powered device. A little fear is a good thing; it keeps you focused. For some, though, the aversion to playing with high voltage is too much, which can cause problems when something fails. So what do you do when you’re reluctant to even open the case? Easy — diagnose the problem with an infrared camera.
[Bald Engineer]’s electrophobia started early, with some ill-advised experiments in transcutaneous conduction. So when his new Sonoff WiFi switch failed soon after deploying it to control a lamp in his studio, popping the top while it was powered up was out of the question. The piquant aroma of hot plastic was his first clue to the problem, so he whipped out his Flir One Thermal Camera and watched the device as it powered up. The GIF nearby shows that there was clearly a problem, with a bloom of heat quickly spreading out from the center of the unit. A few IR images of the top and bottom gave him some clues as to the culprits, but probing the board in those areas once power was removed revealed no obviously damaged components.
[Bald Engineer] hasn’t yet gotten to the bottom of this, but his current thinking is that the NCP1117 regulator might be bad, since it rapidly spikes to 115°C. Still, we think this is a nifty diagnostic technique to add to our toolkit, and a great excuse to buy an IR camera. Or, we could go with an open-source thermal camera instead.
[via Dangerous Prototypes]