Solved! blanck disply issu.

[koushikkchinnu]

My lenovo B40-80 lap is on and bootig is ok but internal disply is blanck...extronal monitor using ok...
How too fix blank disply issu...

 

[webworkings]

If the external monitor is working fine, but the attached one isn't, then there is either a problem with the display, a probably with the cable that connects it, or it is possible they are using two different GPUs and the one is malfunctioning.

If under warranty, I would contact the manufacturer. If not, try a local tech.