Bios access issue X570S PG Riptide

[widow88]

Hello everyone,
I have an ASRock X570S PG Riptide and I can't access the bios settings, I tried several things but unfortunately without success:
With a ps2 keyboard, with a USB keyboard on the usb2 port, with just one memory stick (I tried with the 4 I have), with the "restart to uefi" application, but nothing worked.
When I try to go into the bios the system always freezes, no boot.
Otherwise the system works fine when I don't try to go into the bios (Windows 10 boots quickly, occt tests work without problems, etc....)

I also tried to update the firmware to version 1.50 (with the BIOS Flashback button), the update was successful but again no possibility to go into the bios: the system is still blocked.
I am obliged to turn off the power supply to be able to restart Windows.

My configuration:
Ryzen 5900x
32GB of Crucial Ballistix BL8G30C15U4B.8FE (4*8)
GeForce Gtx 1060
Sandisk nvme
680w Bequiet

Thanks in advance for your help

[widow88]

As additional information, when I try to go into the bios there are lights from the PSC (Post Status Checker) who becomes red and they stays red.
These are the BOOT, DRAM and CPU LEDs
The VGA light is off.

But when i start the computer whitout willing to go in the bios these lights (including the VGA one) goes on and off and when windows is started they are all off.

[MyJules]

you can also force it to go bios screen from windows (on next boot). settings/windows update/advanced option/recovery/advanced startup then reboot. when it reboot, it will go to a recovery screen. one of option there (after a few screens), it will let you boot again to uefi screen.