Motherboard won't boot Windows from the NVMe drive

Desktops and Notebooks
1

Hello, I’ve been dealing with a rather annoying problem regarding my motherboard that won’t boot Windows from the SSD, and it’s given me a lot of headaches over the past month.
I bought a B550m Pichau Danuri and reused my 500GB NVMe Adata Legend 850 Lite that was in my old PC, and when I installed Windows on the SSD, as soon as Windows boots the screen simply turns off and goes back to the motherboard BIOS. I tried changing the modes to UEFI, leaving UEFI and Legacy, turned Secure Boot on and off, did the same with the motherboard’s CSM, and yet it wouldn’t boot even with the SSD set as the boot priority, and that’s because at first it didn’t even recognize the SSD—it was either the SSD or just the USB drive.
I took the PC to my friend’s dad to fix since he works with this, and the motherboard seemed to be having problems, but I filed a warranty claim and the board was functioning perfectly, so I was left with this problem and now I’m waiting for the board to come back with no solution yet. I thought it could be the SSD but it was being recognized on my old PC and recognized on my friend’s dad’s PC; I used it without problems on the old PC but I have no idea what could be causing this problem.
The text got a bit long, but I’m a bit desperate with this situation since it’s my first PC, built piece by piece, and it’s been over a month with this problem already, so it can be discouraging for anyone, right? If anyone has any idea what could be the problem and can help me, I would really appreciate it.

Configuration:
B550m Pichau Danuri
Ryzen 5 5600X
RX 7600
SSD Adata Legend 850 Lite 500Gb
32Gb RAM Kingston Fury Beast
650W Husky Sledgear PSU

2

Test the SSD in other motherboard slots.
And test another SSD in this motherboard to rule out a problem with the board.

It might be unlikely, but also test the RAM sticks with Memtest running from a USB drive (which appears to be working according to your report).

Another thing that could be the cause, though unlikely, is the power supply. Maybe it’s faulty.

3

Grab a USB drive and use Rufus to burn the ISO of a Windows Recovery Environment (I recommend Hiren’s/HBCD since it already comes with several useful tools). See if, when you boot from it, you can access the SSD through it, via Disk Management (diskmgmt.msc). Check how the SSD is partitioned, whether there is an EFI partition (usually FAT with about 16 MB in size). If you used this SSD together with another storage device (another SSD or HDD), at installation time the bootloader might have been written to that other device and the partitions needed for boot may not have been created; in that case it’s trickier to fix.

If the EFI partition is present on the SSD, what I would recommend is to format it and recreate the bootloader files. Use the command bcdboot C:\Windows /s X: /f UEFI, where C: is the partition where Windows is installed and X: is the EFI partition.

4

Just a basic, really silly question, but that could reveal the source of the defect (since Pichau didn’t find any problems):
From where did you download the ISO of this Windows you’re trying to install?
Because it seems to me more of an installation problem with corrupted files than a hardware defect.