I'm having trouble after apt-get upgrade. HDMI output fails. HDMI Monitor is a ASUS VE248. Can repeat the problem with following steps. Write new image Udoobuntu 2.1.1 to SD card. The Neo boots up correctly with HDMI monitor operational. Then get the latest updates with sudo apt-get update and sudo apt-get upgrade. The display is fine when upgrade completes but after reboot the HDMI display is blank. The Neo can be accessed via VNCviewer and seems to be fully functional except for no HDMI output. Connected UART1 to PC and captured process of normal boot and boot after upgrade. Does anyone have an idea of how to troubleshoot this further. It appears that one of the updates causes this HDMI failure of the ASUS Monitor.
Thanks for the response. Fortunately all seems ok to use headless for now and access with VNC viewer.