Comment # 13 on bug 1185601 from Wolfgang Frisch

(In reply to Takashi Iwai from comment #11)
> Is this only about the laptop display (LCD)?  Or are all graphics outputs
> gone blank?

(In reply to Wolfgang Wander from comment #12)
> (In reply to Takashi Iwai from comment #11)
> > Is this only about the laptop display (LCD)?  Or are all graphics outputs
> > gone blank?
> 
> Good call - the HDMI output on the XPS15 is working. Only the LCD (laptop
> display) is blank.

Same here. The laptop display is blank.
Two external monitors are functioning normally.