Full context (see below for TLDR):

I built a custom PC about one and a half years ago, so all the components should still be under warranty (I can provide a full list of components if needed). The PC runs Windows 10 and I use it mostly for gaming and some programming. The CPU is an i7-8700, so there is no overclocking involved.

Yesterday I started getting bluescreens. The first bluescreen happened while I ran a build in Android Studio (i.e., a high CPU load situation). The subsequent ones also seemed to be mostly related to high CPU load. I can boot to the windows login screen most of the time, but as I login (after entering the password), it will bluescreen about 50% of the time. If I am able to login, the system will run fine if left idle, but doing something CPU-intensive will also cause a bluescreen most of the time (e.g. I tried running Prime95, which resulted in an instant crash). Most of the bluescreens were not associated with any specific driver (checked with NirSoft bluescreenview and WinDbg on some of them), except for one that was caused by netio.sys. Also, the bluescreens do not have one consistent code, but are different all the time. Here's a list of some of the ones I can remember:


As this is a very diffuse error pattern, I started suspecting a hardware issue, so I took out the graphics card and disconnected the secondary hard drive from the system. This left a pretty minimal setup of motherboard, CPU, system drive (which is an nvme ssd), RAM (2 sticks), and PSU, as well as 2 case fans and the CPU fan.

With this pretty minimal setup, the system was as instable as before, bluescreening in the same situations as described above. To make sure that this is not a windows or hard drive issue, I also booted into an Ubuntu live system from an USB stick, which was also unstable (i.e. screen freezes that it doesn't recover from) when the CPU was put under load. I also ran windows memchk once, which did not find any errors, so I believe a RAM issue can be ruled out as well.

The system is also not overly dusty, as I clean it regularly, and there is no visible damage to any of the components. I have also double-checked that all connectors are properly connected and even re-seated the CPU.

Based on the fact that the system is mostly unstable under high CPU load, I believe that there is some power delivery issue, which could be due to the motherboard or PSU, or that the CPU itself is broken (but I believe that to be more unlikely as it then probably wouldn't work at all).

Unfortunately I do not have any spare components to do definitive tests to determine which component really is causing the issue, and I also won't be able to get any quickly in the absence of buying them new. Would the best option here to just RMA the motherboard, CPU, and PSU all at the same time, even if I am not sure which one is really broken? Or is there a better way to go about fixing this?

TLDR: I suspect that my CPU, motherboard, and/or PSU are faulty. I do not have any spare components to swap them out and determine for sure which one/ones is/are faulty. Should I just RMA all three components or is there a better way to go about this (e.g., buying new ones to swap out and sending them back once I determined which one is broken)?

  • Run a pass or two of memtest86. If it comes up with any errors, it's either motherboard or RAM. Try to swap RAM sticks. Try to get other RAM sticks for testing.
    – gronostaj
    Jun 8, 2020 at 9:35
  • Thanks for the suggestion. I will try that and report how it went.
    – robert
    Jun 8, 2020 at 11:00
  • I've ran two passes of memtest86 now. It didn't find any errors. I will let it run two more passes, but so far this confirms my suspicion that the RAM is fine. Do you think that makes it more likely that it's the PSU?
    – robert
    Jun 8, 2020 at 13:06
  • It doesn't sound like a PSU failure to me. It's the motherboard or CPU IMO.
    – gronostaj
    Jun 8, 2020 at 14:04


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