I have a Raspberry Pi 3 that appears to have been destroyed this morning. I purchased a no-brand USB mains charger suitable for UK use (and CE certified) from eBay, and I am almost certain that was the culprit. It claims to produce up to 3.1A at 5V. It wasn't the cheapest available, either - I purchased it because it looked of reasonable quality!
It seemed to be working OK initially (green and red lights came on) but the HDMI output did not seem to be producing anything. I decided to unplug it and try a different charger, USB cable, HDMI TV socket, and I got one last gasp out of it (a green light) and then nothing since.
Now, if I plug the device into an old charger that used to power the Pi fine, the chips get extraordinarily hot (like, fire-risk hot), so I think it is sadly beyond repair. The central CPU chip gets to a temperature that easily burns fingertip skin. I have tried waiting for it to cool completely and then try again, to no avail.
I have (bravely and foolishly) tried the suspicious charger in a mifi device, and it seems to charge it OK. So, my question is whether there is a way I can test my charger device to see if it is producing electrical output within USB-defined standards? Are RPis known to be sensitive in this regard?
I guessed there was such a thing as a "USB voltage tester", and lo-and-behold, there is. Would that help?
I expect I would be looking for over-voltage, and not under-voltage. Whilst my understanding of electronic physics is fairly lacking, I guess I am not looking for an over-amperage, since devices take as much as they need?
(In the meantime I have learned my lesson: I'll only use official Raspberry Pi supplies in the future).