@tom I guess the first question I have is, Is the firmware updated on the 7240s?
When you say it suddenly stopped, can you determine an event that could have happened between when it did and when it didn’t work? (like upgrading fog??)
I have the 7240s on my campus so if needed I can go grab one and test. The only time I’ve personally seen this happen is when the system was a Lenovo and in uefi mode the system would download 69% of init.xy and then switch to the black screen and cursor.
Is this the only hardware that is doing this behavior or is it all?
BTW: The video is perfect since we can see how you got to the error. Bravo.