I shorted my arduino nano clone again, so its time to make a tutorial video, how fix this problem.
The schottky diode: 0.5A 20V SOD-123 housing
1. Check the arduino. No power on USB, but Vin working.
2. Check the schottky diode -> yepp its smoked.
3. Replace the diode.
4. Test the arduino
Step 1: Watch the step by step video.
Watch the video.