LinuxQuestions.org - Disabling screen at startup

I currently have a laptop hooked up to a HDMI Monitor. I want to disable the Laptop monitor at startup (i.e. before XOrg), becuse it has some weird hardware problems.

So, I decided to use the video= flags.

Code:

ls /sys/class/drm

returns

Code:

card0 card0-HDMI-A-1 card0-LVDS-1 card0-VGA-1 controlD64 ttm version

So, the card I would disable is LVDS-1

Putting it in the kernel, however, was a different thing alltogether.

adding

Code:

video=LVDS-1:d video=HDMI-A-1:e

gave me a blank screen, with both monitors off, sometimes with a 'out of range' displaying on the HDMI Monitor

adding

Code:

video=LVDS-1:d video=HDMI-A-1:e video=1920x1080@60

gave me a blank screen on both monitors.

Help?