Black screen at startup, G751JY (Only when charger is not plugged in?)

[Kimmix]

I have noticed that everytime I start up the computer and the charger has been plugged in all time, the startup is perfectly fine, no black screen. But if I turn off my G751JY, unplugs the charger and starts it up again a little later, I always get black screen!

Why is this?

[Corporal]

"If it was BIOS problem it should affect every one using that BIOS. No? "
It does.

It's an issue that shows up sporadically. I'm pretty sure every single G751JY has this issue, as both G751JY I returned to the seller and the current one have it.