I wonder if your display is acting up on the BIOS screen, i.e., not liking the resolution and/or refresh rate that the BIOS screen is trying to output.
Maybe try another display if possible.
Also is your display an HDMI ONLY or does it also have displayport inputs and/or old skool VGA as well ?
Could try a different input port and see what happens.
On Windows 10+ you can LEFT-shift +left-click on restart and access a menu that goes troubleshooting->advanced->restart into UEFI or something like that. I do this anytime I’m too lazy to look up how to get into specific OEM BIOS.
try using the boot menu…
start windows,
hold shift key and and restart the computer from the start bar.
the system should start shutting down then go to the blue menu screen where you can select troubleshoot/open bios or eufi.
once open find fast boot and disable it. save and restart, you should now have access to the bios via delete at startup.
Now it stopped working all together. So I tried removing the battery and reset cmos. Then it bootet 1 time to the post screen. Now everything stayes black.
I additional tried:
Screen (With new cable)
using onboard display out ports.
using other GPU
using HDMI on 1. GPU
I really don’t know what to do.
What is my best bet wich part is bricked? CPU or MB?
did you flash the bios at any point?
if so which one. and did you follow amd’s instructions on updating the chipset before you update the bios.
you will brick the motherboard if you didnt perform all steps.
if its bricked then rma is all you can do unless your board has a plug in bios chip.
i just looked and it seems asus bundle there firmware with the bios updates (unlike gigabyte)
so updating the bios shouldnt be an issue.
as its a black screen boot.
turn the computer off at the front.
pull the battery. turn the pc off at the brick and quickly short the terminals in the battery housing.
the residual current in the motherboard should be enough to clear it.
after 10 seconds or so put the battery back in. power the brick, and turn it on at the front.
hopefully the old method of clearing the cmos will work.
if not then try putting a new version of the original bios on a usb. and flashing back to the one it shipped with.
on reboot the system may take a minute or 3 to learn the memory profile and hardware.
so if it reboots or appears to hang.
try leaving it for a little bit (not more than 2 mins).
if still nothing. hit reset and let it try to boot again…
then one more time…
after 3 (max) reboots all hardware should be detected with luck.
if not i would assume the bios bricked. and its time to talk to asus. they are helpful