First and foremost, post your complete build (including PSU). The more information you provide the better assistance you will receive.
Now for the obvious:
Have you ever been able to boot with display, or nothing from the start?
Have you recently removed or otherwise messed with your GPU (including cabling)?
Have you recently updated your BIOS, drivers, or Windows?
Are your cables (from GPU to Monitor) securely fastened, and plugged into the correct ports?
Is your monitor plugged in, both video and power?
Remove and re-seat your GPU, and ensure all power cables are plugged in as required.
I'm assuming you get ZERO display, and therefore cannot see BIOS, is that correct?