I’ve got a mangOH WP series dev kit with wp8548 in my hand. I got a problem powering this little thing up. When I connected the board and my PC with USB cable. the typical story is that only the PWR LED turned on, and my PC cannot even know there is new hardware connected, so the device also cannot be PINGed . There were several times that I could connect successfully and everything worked fine. Is there way I could diagnose or fix?