I have Lenovo U330p laptop with Win8.1 and an external monitor (HP ZR2330w). The monitor is connected with DVI(monitor end) <-> HDMI (laptop end) cable.
The setup has been running fine since Jan 2014, but this week I moved my desk to another room. (disconnected and powered off the monitor and connected back again in the other room) Nothing special IMO.
After I physically moved the system, Windows has been able to detect and use the external monitor only occassionally.
More insight to the problem:
Occassionally means, Windows detects and uses the external monitor only when I uninstall the display adapter (Intel HD Graphics family) and monitor (Generic PnP Monitor). Then Windows automatically re-installs the drivers, and that makes the setup work UNTIL next time the monitors go to sleep. After that, the external screen is gone from Windows Device Manager and from both Windows Screen resolution pane, and Intel Graphic properties pane.
The screen is physically fine. It starts everytime normally and looks for signal. It goes to sleep when no signal is detected.
The cable is fine, because the screen notices when I plug on/off the cable. Also, the setup works after software changes (as described above) without touching/changing the cable physically.
I have installed latest drivers for the HP monitor and for the Display adapter (Intel).
The problem is not random. It happens every time systematically. (Win8 systematically kicks the HP out every time it gets the chance ;))
I don't know what factors could affect this, and don't have any ideas left, where to continue troubleshooting. Any help or suggestions would be appreciated. Thank you.
I switched input source manually to DVI instead of Auto in the screen as suggested. That didn't help.