Device: Samsung Chromebox i5 I/O edition
External Monitor: HP2711x
Cable: (not specified)

Spun off from Issue 631182:
"Same issue ("Dear monitor") with Samsung Chromebox i5 I/O edition on my dual monitor setup. I run a HP2711x on the left and a Samsung S27B550 on the right and have for a well over a year and recently I have been getting the message about the HP model and it will occasionally black out and come back. Tried swapping ports and the HP is still having issues. The HP works fine when I connect to external port on OSX from my Macbook so I am ruling out faulty monitor, cable and port."