Hi all...when I try to switch to discrete graphics by fn+f7 the system reboots but no screen...only keyboard light up and Alienware logo head flashes 7 times(which I think is LCD error).

Anyway I am able to reset BIOS and screen again comes up with normal boot but with integrated graphics as default, gtx 1070 also works fine no problems.

The problem started when I tried to update vbios of Nvidia within discrete graphics mode earlier this week.

Everything else is ok But now I cannot choose  discrete only mode ....any help would be appreciated...Thanks