I wanted to externally power my Arduino. The specs on my external PSU showed 18V DC output. On the limit, but should be ok. I connected it to my Arduino. Found out that this killed my Arduino. After measuring the PSU, I measure 24V DC!!! So something wrong with that PSU for sure.
If I now connect my Arduino with my PC, it has issues with USB. Device Manager says "Unknown USB Device (Device Descriptor Request Failed)". Although, the Power on LED is on, and I see the on board LED flashing twice. So I guess at least something is still working. Maybe it just corrupted the boatloader? Can that be?
Anyway, any experts here on this forum with some ideas? Can I do some checks, or measure something on it, to identify the issue? Would be nice to recover from this 50 EUR disaster
(PS. I already ordered a new one - this time a cheap clone or less than half of the price - just want to see if they are as good as this one).