Finished building my new system as following (GPU from old system):
CPU: 3700X, MB: MSI B550 PRO-A, GPU: Sapphire RX Nitro+ 580 - 8GB, RAM: CORSAIR 16GB DDR4.
Issue: I can not see Motherboard splash logo, POST, Windows loading, I cant access BIOS via pressing delete buttom or by going trough Windows Recovery. - It just goes straight into Windows Log on screen.
What I tried:
Another monitor, another HDMI/DP cable, clearing CMOS, Updating BIOS (via BIOS FLASH BACK), updating AMD Chipset/GPU Drivers and reinstalling windows. GPU BIOS is up to date.
Using a Nvidia GPU, I can see the MB splash logo, windows loading and I can access BIOS with no problem - I enabled UEFI mode while I was in BIOS - Still the problem comes back with a AMD GPU.
I don't really want to swap GPU'S when I want to go to BIOS. So has anyone faced a similar issue with a fix?
I had a similar issue when I upgraded to a Ryzen 3700X using a Nvidia GTX1070 GPU Card.
No video output during POST only when Windows started to load.
Needed to enable CSM Mode in BIOS in mine Asus Motherboard and reset my 4k Monitor to default (Connected both with DP and HDMI). But the only way I was able to get into BIOS and to change any settings was because I had my 2k Smart TV connected via HDMI and I did have video output to the TV set.
Once I enabled CSM Mode in BIOS I started to have video output during POST and am now able to enter BIOS when needed.
NOTE: When I reinstalled my Motherboard's BIOS it automatically enabled UEFI Mode so I needed to disable UEFI and enable CSM mode.
When it is in UEFI Mode I got no video output during POST and I wasn't able to see nor enter BIOS Settings. But once Windows started to load I had Video Output to my 4k Monitor.
CSM was enabled out of the box - while it was enabled it also did not send signal to two different (ViewSonic 1440p & LG 1080p). Under old system (intel 3770k, Asrock Z77) everything worked.