Are you willing to send your system to us?
Outside of Germany: No.
Is your system a laptop or desktop?
Laptop
What is the make/model of your system?
Dell XPS 15 (L521x)
What is the model of your CPU?
Intel i7-3632QM (Intel HD 4000)
What is the make/model of your failing display(s)?
Original Dell Laptop Screen + external Monitor HP Z27x
If laptop, is your built-in display failing?
Yes, and if I'm choosing "duplicate" the external Monitor turns black as well
What is your operating system?
Windows 7 64-bit
What display driver version do you have installed?
10.18.10.3621
What type of connection are you using? (HDMI, VGA, DP, DVI?)
- Internal connection (Intel HD 4000) for internal screen
- DP (NVIDIA GeForce GT 640M) for external monitor
What happens that results in the blackscreen failure?
It happens randomly if:
- I change the screen resolution of the external monitor (manually or through an app like a game)
- if windows has turned off the displays through the energy settings and I move the mouse to turn it on again
In both cases the external monitor will never become black. Only if I choose "Duplicate" through Win+P the external turns black as well. This is strange as the external monitor is connected to the DP port of the Nvidea GPU.
In 100% of all cases I was able to turn on the screen by pressing the power button which turned the Laptop into sleep mode (led is blinking). But since updating the Intel HD 4000 to the recent version and updating the Nvidia driver to the recent version 340.52 (9.18.13.4052) I need sometimes multiple tries to turn on the screen again by this trick. Unfortunately I don't know which of the updates made the situation even worse.