My computer is stuck at the access bios screen

[xBaeCon]

Most of the time when I turn on my computer, it says that there is no signal and that the monitor will go to sleep mode in a few moments. Other times when I restart the computer from there, the asus screen pops up where it says to boot up bios by pressing f2 or delete. After a while of restarting, the main screen where I put in my password finally shows and my computer is totally fine after that. Can someone help me with my problem?

I have an Asus z270 a prime motherboard and an lg 34uc79gb connected with an hdmi

 

[MickyDee]

A curiosity question: when you get the first sleep prompt do you wait to see what happens or do you hit restart? I ask because when I start my computer I almost always get the message from the main monitor that it is going to shut down in power saving mode, then after about 30 sec. it will sit and spin the little dots and then bring up my logon screen to enter my pin # The whole process can take a min. and a half if not longer. Are you hitting restart when you see the sleep mode message? If so try letting it go and see what it does.