don't panic!!!
Some devices requires to be switched ON to allow USB connection... my Meizu M3 acts so.
Maybe this RAMOS RM100 need to be in that status to recognize USB signal... and RAMOS firmware maybe do not have a short cut (like the nice combination you have explained) to put the device in upgrade mode (rockusb)
I am dealing with it right now, any further advance will be explained here.
