u/RyanFromTheCorner

Hi guys, could really use some opinions on this because I’ve spent ages troubleshooting it and I’m starting to think my 5800X might actually be faulty.
My system is:
MSI MPG X570 Gaming Plus
Ryzen 7 5800X (upgrade)
Ryzen 7 1700 (old CPU that I’m using for comparison)
Hyper 212 Black cooler
16GB DDR4
Windows 10
BIOS E7C37AMS.AR4, build date 13/08/2026
Windows installed on a Fanxiang S500 Pro 256GB SSD
Basically, the PC was working with my old Ryzen 7 1700. I upgraded to a 5800X and started getting constant random blue screens/restarts.
The stop codes aren’t even always the same. I’ve seen things including:
KMODE_EXCEPTION_NOT_HANDLED
SYSTEM_THREAD_EXCEPTION_NOT_HANDLED
IRQL_NOT_LESS_OR_EQUAL
The crashes can happen extremely quickly, sometimes when the PC is basically doing nothing.
Here’s what I’ve tried so far:
BIOS: The motherboard is on E7C37AMS.AR4 from August 2026 and detects the 5800X correctly. BIOS itself seems completely stable. The 5800X sits around 38–39°C in BIOS, so it doesn’t appear to be overheating.
RAM: A-XMP is disabled and the RAM is running at 2400MHz. I’ve also tested using individual RAM sticks in A2 and the crashes still happened.
PBO: Found Precision Boost Overdrive under AMD Overclocking and disabled it for testing. Made no difference.
Windows: I originally wondered whether Windows/drivers were corrupted, but I booted directly from a Windows installation USB and the PC still blue-screened while sitting in Windows Setup. So it doesn’t seem to be my actual Windows installation.
I’ve also previously done a clean Windows 10 installation, so I’ve already spent quite a bit of time ruling Windows/boot issues out.
CPU cooler/mounting: I wondered whether I’d overtightened the Hyper 212 or seated the 5800X badly. I loosened the cooler previously and it made no difference.
Today I decided to do a proper CPU comparison.
I removed the 5800X and put my old Ryzen 7 1700 back in. Ironically, the 1700 had previously had some bent pins that I carefully straightened. I checked them, installed the CPU properly, fresh thermal paste, mounted the exact same Hyper 212 and booted it.
The 1700 booted straight into Windows.
I left it sitting at the lock screen and desktop and it was stable. Restarted into BIOS and it was still completely stable. CPU temperature was around 33–35°C.
I then removed the 1700 and reinstalled the 5800X extremely carefully.
I checked the 5800X pins and they all look straight. It dropped completely flat into the AM4 socket without force and I locked the lever normally. Cleaned both the CPU and cooler, applied fresh thermal paste and remounted the Hyper 212 evenly in a cross pattern. I deliberately didn’t crank the cooler down excessively.
Booted the PC and the 5800X actually made it all the way to the Windows lock screen.
I thought I’d finally fixed it.
Then after sitting there for a few minutes without me doing anything, it blue-screened again with:
KMODE_EXCEPTION_NOT_HANDLED
So at this point the comparison is basically:
Ryzen 7 1700 = stable
Ryzen 7 5800X = random BSODs
Same motherboard.
Same RAM.
Same GPU.
Same PSU.
Same SSD/Windows installation.
Same cooler.
Same everything apart from the CPU.
I’ve now gone back into BIOS with the 5800X and loaded Optimized Defaults as one final test. A-XMP is off, RAM is at 2400MHz, the motherboard detects the 5800X correctly and it’s around 39°C in BIOS.
Is there anything else BIOS/voltage/CPU-related that you guys would test before I call the 5800X faulty and return/RMA it?
The fact that the 1700 works in exactly the same machine but the 5800X even crashes from a Windows installation USB is what’s making me think the CPU itself is the problem.
Any ideas appreciated because this one has been driving me mad lol.