deskmini a300 boot problem

I have just set up my new a300 (outfitted with an athlon 200GE, 8 gb ram, sata-ssd) and installed windows 10 home. the system came up fine (at first) and i started the windows update process to install the latest updates. I had to do several reboots and after one of those, the system did not come back. All that appeared on the screen was a dotted circled, singalling an ongoing process going on, after a while even that disappeard and the screen went black. The system did not shut down, obviously it was hanging at some point before booting into windows.
I can restart and enter the uefi-setup, but i can't find anything useful to change there. I tried to reboot into my windows setup-stick and to reinstall the OS, but it won't boot from the stick as well.
I tried to find a solution in the forum. I found a hint at a possible problem with the used memory slot, so i flipped the ram to the other slot, but that did not change a thing.
Some people have reported problems with the video-configuration, some similar issues seemingly could be addressed by resetting the CMOS, but I am unsure as to what to try next.
current bios is ver. 3.5
thankful for any hint...

Following a hint from Asrock-Support, I detached the disks and was able to boot to bios (uefi). Turned out that one of the two sata disks i had installed was bad. After tearing that disk out (it was a preused one, installed in sata 2) the system came back.
Nevertheless i updated the Bios, everything continued to work fine.

However, after adding another spare (preused) disk to sata 2, that disk also failed after a short time. Again, the system is fine after removal of that disk. Like the disk before, the drive is no longer accessible on another system.

This makes me wonder whether maybe the A300 killed both disks. Has anybody had similar problems? Right now, i am using just one disk in sata 1.

The system is running fine with just one ssd being installed on sata 1 port. I have checked that ssd with both sata cables provided and had also hooked it up to the other port; it was functioning fine with either cable and port.
therefore i don't think that the cable is the problem. If the problem does not relate to the hdd-s having been used and worn-out before, it might be that the system is "overwhelmed" when 2 drives are connected. Perhaps the power needs of the additional are too much?

I'm seeing the same problems as you with just one NVME - I get one boot per CMOS clear - ASRock did not indicate to me that fixed firmware is on the way. Perhaps if we make enough noise they will fix this bug.

Same problem here.

Have just bought an A300, installed with Athlon 3000G, Noctua cooler, 2x4gb Crucial Sodimm and 2x1tb Crucial P1 NVMe SSD.

Installed Ubuntu 20.04 to an USB, and after rebooting from the install I get a blank screen, no Bios access, no booting.

The only solution was to clear the cmos, then I was able to enter the bios, boot and Ubuntu was working, thought I was some glitch, installed and configured things in Ubuntu, restarted and again, blank screen after rebooting.

Once again I cleared the cmos, and I was able to enter the Bios, the version of the bios was 3.5 so I updated it to 3.6.

I then installed FreeNAS to give it a try, installed and restarted without a problem, I tried couple of times so I thought the problem was solved.

I wasn?™t happy with FreeNAS, so I decided to go back to Ubuntu, now I installed Ubuntu but in one of the NVMe disks, installation run without any problem, and at the time of restarting, again blank screen, no bios access no booting, nothing.

I will have to clear the cmos AGAIN in order to be able to do something.

This is really annoying, Asrock should give us a solution really fast.

I have this very clear, this is solved within a week or the case is going back and I will give very bad opinions about A300 setup.

Could it be a UEFI problem? Read about this kind of problems in Ubuntu forums.