Almost the same here. Firehawk FX doesn't start, just shows firmware version on display, and red "A" button is blinking. Helps only "soft" resetting 1-3 times. I flashed every possible firmware version, made factory resets - unit may start 2-3 times in a row, but after switching off for a half an hour always ends with blinking "A".
Opened a support ticket.
Added video: https://www.youtube.com/watch?v=nAC1Xd_8lYU