When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list the specs to your build like so:
CPU:
CPU cooler:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the age of the PSU apart from it's make and model. BIOS version for your motherboard at this moment of time.
I don't see any mention of a discrete GPU. If you are using a discrete GPU, then remove the GPU and connect your display to one of the motherboard's display output ports.
See if you're able to recover your BIOS using the CrashFree BIOS 3 feature;
https://dlcdnets.asus.com/pub/ASUS/mb/LGA1700/PRIME_B760M-K/E21845_PRIME_B760M-K_UM_WEB.pdf?model=PRIME B760M-K
page 2-4 in your motherboard manual.
Is the BIOS dead? What can I do to fix this?
If the BIOS is conked out, you will need to RMA the board if it's brand new. If you're out of warranty, then you're going to need a CH341 A BIOS programming toolkit and reflash the BIOS, if the BIOS is what got knocked out. Mind you, if the board is tampered with via the CH341A BIOS programmer toolkit, while you're yet under warranty, you can void your warranty. Which is why I suggested RMA'ing the board first, instead of second.