Mine is doing something similar. If I power-cycle the device, the connected ethernet port and power indicator light up but nothing else. No flashing boot sequence at all. If I unplug and hold the reset button for 6 seconds while powering on, the device boots into the saved "User Default" configuration and works normally.
Before discovering that I could save and boot into the saved "User Default" configuration, I assumed the device was bricked and did a factory reset as well as re-loading the firmware from the bootloader (eg. http://192.168.1.1/index.html).