BBB powering up problem

I got a problem. When i connect 5V PSU only pwr flashes 1 time. And If i use only USB host Port with USB cable, BBB Works normally. Are there sonething broken or what?

https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!msg/beagleboard/n0dbCn2RsG8/e9MJzEoFAQAJ

Regards,