Question PC Stuck on Preparing Automatic Repair Loop PLEASE HELP

[soorajt]

I have had my PC built for the past 4 months now and I got a new CPU cooler today. I installed it and I tested it out by building it outside the case (like a test bench) and it worked fine. Only problem was when I put it inside of the case.
I started up my PC after assembling it in the case and it tried to boot into Windows 10, but it said "Preparing Automatic Repair" near the rotating circle and the display would turn on and off repeatedly and then after a few tries it would completely turn off. It couldn't boot into Windows. After that I entered the BIOS, where it was fine at first but now it boots in but the screen just turns on and off, basically forcing me to restart the PC with the power button. I tried bringing it back outside of the case, but the same problem still occurs. I have read the other Reddits posted, but it seems most of them have reached a blue screen, where they can access command prompt and such, but that only happened for me twice. I have also only seen the diagnosing your PC part three times. I was actually running a beta version of my BIOS before (yeah I know dumb move), so I downgraded it to a stable version, but still no fix. I also tried reinstalling Windows, but it will not carry though to the install page, but just turn off and on. I tried installing Linux, but that didn't work either.
I am out of ideas so please help!

PC SPECS:
CPU - AMD Ryzen 5 3600
CPU Cooler (new; using stock before this) - Cooler Master 212 Evo
Motherboard - MSI B550 Pro-VDH WiFi
RAM - G.Skill Ripjaws V 16GB 3600 MHz
Graphics Card - ASRock Phantom Gaming D3 Radeon RX 5600 XT
PSU - Corsair CV550
SSD - WD Black SN750 500 GB
Case - Cooler Master Q300L mATX

 

[Tfo052]

Hello, the first thing you could try would be to install windows using one stick of ram at a time and swapping the ram between slots and sticks to determine if something is broken there, as failing ram or a bad ram slot can cause weird issues like this (not turning on, sometimes turning on, corrupting data on the drive) as it is read from ram.

If that does not work, try removing the m.2 drive and any other peripherals (other than mouse and keyboard) or drives you have plugged in and see if it boots to bios and is stable there.

 

[soorajt]

Thanks for your response.

I have tried different set of RAM sticks and the problem still persists, so I don't believe the RAM is at fault here. I have booted without the M.2 as well and it can go into the BIOS. The PC cannot boot properly into a USB Flash Drive, so I don't think the SSD is at fault. I reseated the CPU and the problem still persists, but I don't think the CPU is at fault, because it is getting too far in the boot process for the CPU to create any issues. I believe the problem is with the motherboard, as the keyboard, mouse, and monitor all turn off when the monitor goes on and off, and the motherboard essentially restarts itself. I don't think PSU is bad because I has been working fine for the past months, and I believe GPU is fine as there is something outputted. I have requested RMA for the motherboard and will send it to see if it is the problem.