I think this is related to a rookie mistake that I made. I recently picked up a breadboard power supply. Like a putz I ran the 5v from the power supply to the VIN pin on the Arduino instead of the 5v pin. Since then I get an error when trying to upload to the arduino unless I power it externally (battery).
I've done a little testing, and running off USB the 5v and the 3.3v pins measure 2.81v. But, when powered by a 9v battery they test at 5.06v and 3.31v respectively. My first thought was a bad voltage regulator, but if I'm not mistaken that would cause the external power to have the same problem, right?
I'm a bit of an electronics noob, so I'm looking for some guidance on how to diagnosis what is bad on the nano. Any help is GREATLY appreciated. Thanks!
knut_ny - I think you might be right. Based on your advice, I found a few posts talking about the diode being toast and describing exactly the symptoms I'm seeing.
But, my nano is an eBay special and doesn't seem to match what theirs look like - so I'm not 100% positive which component is the diode I should replace (very, very new to all this). I've attached a couple of photos showing my nano. I think the diode is the small black component on the left side of the bottom, is this correct?
Looks like correct.
If u could be sure that your nano is fed power from one soucre only, u can try solder a jumper wire accross the diode. (the diode may be removed or not)
This will connect USB-power directly to 5V.
Do NOT connect two power sources until the diode is replaced.
