I have a very strange issue with my Arch Linux install.
When a HDMI cable is connected to my graphic card (a GTX 970), my PC won't boot, it only shows a black screen, but it will start if the HDMI cable is disconnected.
If I plug in the HDMI cable while Arch runs, the PC freezes.
I have the same issue if I use the DVI-D port.
At this time I'm using Display Port and DVI-A do not have this problem.
How may I approach this? Which logs would be useful?
EDIT : I later found this happens when i plug a third screen using any connector. Another strange detail, 3 screens are working only if i plug the third one (DVI-A) during the boot; if I plug it before, it won't start, and if I plug it in after boot, the PC freezes.
EDIT 2: Thank you for your answer ! This is not a laptop but a tower i build myself with: