Are you sure you didn't accidentally get 12V onto the 5V rail when clearing the short?
I don't understand... You mean like when I shorted the ground to actually charge some caps that when I stopped the short discharged in the 5V rail? Or if I also accidentally afterwards touched also the 5V rail?
Fo the first one, I don't know, I'll have to check the Arduino schematics and see what I can make of it, but I didn't had any caps other that those. On the second one, I'm sure that the only thing that wire touched that shouldn't have was the common ground.
I don't have a schematic so I don't know what type of regulator it is, but this can cause damage to some chips.
If I'm not wrong, the regulator in the Arduino is an
LP2985, which, if I understand correctly, should witstand up to 16V.
You would have to read the datasheet if the Vreg and see what they say regarding the protection diodes vs caps size.
I'm afraid I'm too much of a beginner to understand that
Or try to replace the regulator.
I'll add it to the "to be replaced" parts list.
Thank you!