Display only works with External Monitor

[ealad]

So for some reason, my fairly new lenovo y570 ideapad only shows the display when plugged into another monitor, lcd or not. Everything else works, the sound is coming out fine, but I just wish I knew how to get my display working again. Any ideas?

[yigit]

press fn + f3 or windows + p

[ealad]

Then what do I do? When I press either combination, it brings up 4 options. Ive tried them all, but my laptop monitor still does nothing. The only thing thats different now is that the backlight turns on, but I still cant see anything. 

[yigit]

are you able to see the screen on your lenovo when another monitor plugged in or not able to see your screen at all?

[ealad]

Nope, I can only see stuff on the external monitor. The actual laptop monitor doesnt show anything, only the backlight works.

[yigit]

if you don't see lenovo logo at start-up, possible lcd or connector cable issue.
call lenovo support line.