Ever fried a component by accident - share your most costly electronics Blunder

[Alan]

Have you ever accidentally fried a component? We’ve all been there just one little mistake and suddenly, there’s that dreaded magic smoke. What’s the most costly or painful electronics blunder you’ve experienced and what lessons did you take away from it?

 

[12Cronut]

believe it or not, early in my career, I destroyed a rare, custom-built power amplifier module that was irreplaceable that's worth about $4,000 back then. I wired the main 24V input cable with reverse polarity.
since then, I always remember to use polarized connectors, even for internal power wiring. If you must use header pins, make sure your mating connector is keyed, or, at the very least, physically block the reverse orientation using a piece of epoxy or hot glue. Never rely on color coding alone!

 

[barfle]

I was working on a single-ended transformerless power amplifier. The output was capacitively coupled, and I hooked up the speaker to the wrong side of the output capacitor. At first, I thought it sounded strangely tinny, then the woofer’s voice coil caught on fire.

There is the old joke about electronic parts working on smoke. Once the smoke gets out, they stop working. I’ve definitely let the smoke get out of many parts over the years.

 

[Alan]

Wow those sound like some seriously pricey moments of magic smoke. I bet those memories will stick with anyone. Thanks for sharing the lessons learned… and that hilarious story about the voice coil catching fire!

 

[oldgeek]

I have exploded a few electrolytics that I have wired backwards, usually on the negative supply. Some of the smaller ones actually create a louder bang than the big computer grade cans, but you can't beat a 50,000uF can for shrapnel.

Another story, if you can spare the time:

There was one long night in tech school that I remember so clearly. I had been at school since 8AM. It was now 8PM and my last class--Radio transmitters and receivers--it was two hours of lecture. The teacher was starting to lecture on Colpitts oscillators or something equally boring and I just wanted to close my eyes and sleep.

It was then that I spotted an innocent little resistor on the bench. There were power supplies on the bench as well, so I put the resistor across the terminals and cranked up the voltage. My goal was to keep the resistor smoldering as long as the lecture lasted, about 110 minutes. I succeeded. The teacher never said a word, but took it out on me at grading time. It was the only B I ever received in a tech class, there were some Bs in other classes, but I wanted to ace anything related to electronics. He told me I was insolent, hence the B. No, I said, I was sleepy and bored. He told me I could challenge the grade with the department head but I thought better of it. That might just turn a B into a C.

 

[Alan]

Haha, that’s a mix of terrifying and impressive. Backwards electrolytics and slow-cooking resistors, definitely classic hands-on learning.

It seems like you were more curious (and maybe a bit tired) than defiant. A single B for a resistor that’s smoldering? Honestly, that’s a pretty legendary deal.