Mac Firmware Update M3T105 - Additional Notes which may be of interest

Additional steps beyond the firmware update instructions:

1. Once firmware update completed (waited appropriate amount of time after monitor screen went black), as directed turned off the monitor, unplugged it and re-plugged.

2. Screen was still black, then had to shut down my computer and restart, screen returned as per normal, logged in and the initializing firmware screen (in progress) reappeared - cancelled it immediately.