by sdjf » Tue Jul 01, 2014 12:39 am
Not sure I completely follow you, but I know that sometimes when my usb screen gets disconnected, and I reconnect the power to it (pi still running whole time), the pi gives it a different device reference. If I want to get my startx command to work again, I type blind "ln -s /dev/fb2 /dev/fb1", since X expects to find the display at fb1 and Pi put it at fb2.
the other thing I did was write a script I called lsfb, that I can type and have the Pi tell me via my speakers which fb devices it sees!
so, another thought for debugging, is pipe any command to flite and see what the pi says to help debug. it might talk too fast, so for regular debugging stuff, I wrote scripts that have names that are easy to type.
maybe your fb utility does what I mentioned above, am not familiar with it. But you might want to make sure that the pi knows where to find the display.
changing to alternate terminals should not work unless you have logged in to them all, as far as I know, but then my setup is odd - pi sees it as headless as no standard monitor. Have USB keyboard and USB monitor, and after a reboot, have to log in blind to start x again.