I had a slightly different boot hang symptom about three times on a recent shoot (only my second shoot) on two different bodies. All on cradle battery power, Red Drive and LCD only. All with 48V phantom power on Channel 3, Sennheiser 416, and Denecke timecode box input.
After pressing the power button, the rear LCD would flash on and off repeatedly (no "Booting" words). Didn't have time to see if it would eventually start up. Rebooting with nothing plugged in seemed to work.
After pressing the power button, the rear LCD would flash on and off repeatedly (no "Booting" words). Didn't have time to see if it would eventually start up. Rebooting with nothing plugged in seemed to work.