I have a ProBook 450 G3 and have an external monitor connected. It is an Acer S241 24" monitor. It is new.
When the monitor is connected, the laptop screen and monitor both go blank for several seconds, several times per day. The lenght of time that they are blank ranges from 2 to 30 seconds. In ALMOST all cases, they eventually come back -- once in a while the time is so long that the user restarts the pc so I don't know if would have come back or not.
For troubleshooting, I replace the Acer with a old Dell 19" monitor. The issue occurred once in 5 weeks with this montior.
I connected the Acer back yesterday and tried to update the HP drivers but the drivers were current. (although I did reinstall them).
Does anyone have any other ideas? Any help would be appreciated.