Probably more experienced users will not have similar issues, but I'll provide my solution just for for the record:
Power off devide.
Insert SD card into the slot.
Hold 'boot' button on the mainboard.
Plug in device.
Release 'boot' after 5 seconds.
Power off and power on.
in my case it took up to 60 seconds before my device boot from SD card.
I checked the same with USB and it also work (*it ust be plugged into one of USB2.0 ports).
Thank you for your suggestion. I'll close the thread.
