hello there navalka.
i had the same problem when i tried starting my BPI-M1+ for the first time.
to get the proper help it would be great if you could tell us what LED are blinking/lightingup when you try to power on your BPI...
what solved my issue was:
first problem finding a good power supply, i ended up using LED strip power supply 65W 12V and i added car charger 5V 4A to power my BPI
second problem for me was the USB cable i had to buy proper high quality USB cable to connect the car charger to my BPI (shorter is better)
third problem was the microSD card that i was using, it was saying that it is class 10 but when i tested it was actually class 4 not 10, i bought Kingston original C10 card and BPI started working instantly...