U3011, access menu/factory reset without Input Source

I'm having the no-wake-up-after-sleep problem endemic to the U3011 (and other?) dell monitors. This only seems to be fixed by power cycling the monitor, but even then it is intermittently fixed. I _think_ resetting the monitor to factory and disabling DDI/CI helps (although this may be apophenia). Unfortunately, I can't seem to figure out how to access the menu to factory reset the monitor when there is no input source. Is there a way to do this? Without an input source the monitor displays "no X connected" and the button press brings up the menu to choose input sources only.