Stuck on black screen boot

[CultHero]

My late 2013 rMBP just started doing the black screen intermittently upon startup and wake from sleep. Usually resolves itself, but not this time. PRAM and SMC reset, nothing working.

Can't get past black screen. What now?

 

[cassini007]

Happens on my 2013 MBA sometimes. I would try closing the lid for 15 seconds when the black screen comes up, and then reopening it. Works for me most occasions.