Below solution is if you have connected a monitor to your motherboard or graphics card and are not able to go into BIOS because on turning on your PC, the first thing you see is windows OS. I have this working for the following interfaces: HDMI 1.4 graphics to HDMI 2.0 Monitor port, mDP graphics to DP monitor, mDP graphics to HDMI 2.0 monitor port.
This worked for me, run the optional steps too for better luck:
Turn on your CPU
Keep an eye on your keyboard/mouse light to know when your USB devices get powered. As soon as you see the keyboard/mouse light up, start pressing DEL
Your CPU should now be going into BIOS although your monitor is still blank and not showing anything.
(Optional) Wait for 10-20 seconds just to make sure it has entered the BIOS. To make sure the BIOS is up, pressing ALT+CTRL+DEL should restart the CPU. Repeat steps 2 and 3.
(Optional) Press F9 then left arrow then ENTER to reset BIOS to defaults. Your PC will not restart after this.
Press F10 then press ENTER.
Your CPU should restart and now you should be able to see the BIOS option, hit DEL key to enter bios like usual.
My setup as far as this issue is concerned:
GIGABYTE 990FXA UD3 R5
Acer 32" 144Hz 1080p Curved connected via DP 1.2
MSI R9 280X connected via mDP/Thuderbolt-2
ImDaMan got a reaction from user73 in Post Screen/BIOS doesn't display with DisplayPort