Question Intel i5-8400 CPU causes BSOD with random errors

[Kokufuu]

I have received a faulty PC from my friend and was able to pinpoint out that the CPU causes the problem.

Symptoms and what I have tried:

• the PC won't boot, goes into BSOD after a few seconds
• able to get into BIOS
• tried with freshly installed OS and with USB boot as well
• tested all other component on different machine, all runs fine (motherboard, RAM, SSD, etc.)
• after BSOD Windows tries auto repair but fails and gets back to the BSOD loop
• the BSOD error messages are randomly:
  • System thread exception not handled
  • Unexpected kernel mode trap
  • Page fault in non-paged area

Is there any tool which I can run on boot before the OS to test/check the CPU. I'm thinking about something memtest86 for RAMs.
I'm willing to try out anything as it can't get any worse and will throw it out if it's now fixable.

Thanks in advance!

 

[Lutfij]

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list the specs to your build like so:
CPU:
CPU cooler:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the age of the PSU apart from it's make and model.

How did your friend narrow it down to the CPU and not a corruption in the OS or missing/corrupt drivers?

freshly installed OS
Where did you source the installer for the OS?

 

[Kokufuu]

CPU: Intel i5 8400
CPU cooler: stock
Motherboard: AsRock H370M Pro4
Ram: HyperX Fury 2400MHz
SSD: Crucial MX500
GPU: none
PSU: Corsair Cx450M (half year old, barely used)
OS: Windows 10 (official MS site ISO, Rufus)

"How did you friend narrow it down to the CPU and not a corruption in the OS or missing/corrupt drivers?"
I only received the motherboard and the CPU from my friend, all other parts are mine which I used several times in other builds.
Tried 2 different RAMs, also checked with memtest86, both are fine, one of them in daily use.
Received motherboard works perfectly with another CPU of mine.
Also tried with an Ubuntu Live, that gave kernel panic at the same way as Windows gave BSOD.
Both OS were freshly installed and worked fine on another test machine.
So it is 100% that the CPU is faulty.

 

[Kokufuu]

Any ideas @Lutfij ?