The pins are giving 12v power output, as log as i connect the Arduino straight to a computer or phone charger. And a other power adapter to power the led strips via Vin. This works fine.
What does not work: Powering the leds with the same 12v poweradapter en the USB via a power converter that is connected to the same power adapter as the led strips.
Is it maybe due to the GND?
See attached picture
