Pi not booting with universal power supply

Hello everyone,

hope you can give me some advice.

I try to power my banana pi m2 ultra with an universal power supply with 5V and 2250mA. When everything is plugged in nothing happens. After i press the power button, first the red led flashes and after one second all three leds are flashing for another second. I tried two different power supplies, but nothing changed.

I’m running Ubuntu Mate 16.04 installed on emmc. Using the USB-OTG connector the pi starts immediately.

Is there anything i need to take into account when using the dc-in port?

Thanks in advance!