Question My computer keeps restarting randomly. Narrowed it down to either the power supply or the motherboard

[cheesemars]

A couple days ago, my computer hard restarted. I didn't think too much of it, but about 5 minutes after it booted up, it restarted again. At the beginning, it lasted between 2-7 minutes before restarting again, but now it's just in an endless restart loop (about 2-5 seconds) and the only way to stop it is to unplug it. I've disconnected the GPU and switched out the hard drives in a hail Mary, but it didn't effect it any.

Also, sometimes the GPU starts and sometimes it doesn't. When it doesn't start up, the fans shake; as if they're trying to spin but they don't have enough power? Which leads me to believe that it's a motherboard problem because, even if the power supply isn't hooked up to the power supply, the motherboard should provide power to the fans (which it does when the GPU decides to work, but not often anymore).

It's an i3 (not sure which one), an MSI H81M-P33, an EVGA 500B, and an R9-380, if that helps any.

Thanks.

 

[cheesemars]

So how are your pc doing right now? What was the problem? I have same issues 🙁

That's a shame, sorry to hear that. I wish I could be more help, but the issue was never definitively solved. The computer was outdated when I built it and I'd been having issues with it for too long; I ended up building a new one.

Something that may help: before I built my new PC, I tried using the new PSU. The new PSU was way overpowered for what the old PC needed and that still didn't fix the issue. I think the only parts I didn't try to replace were the CPU and the RAM. In hindsight, I'd probably lean towards the CPU; I did take the RAM out, swap them, try running the PC off one or the other. It should have worked if one of the sticks were bad. The likelihood of both sticks going out are pretty low. My bet would be on the CPU. Just in case, I'd try removing the old hard drive and swapping in a different one, or try booting to a flash drive, or just nothing at all if need-be.

Sorry I can't be more help on this one: it's been a long time and I never actually fixed the issue. I hope all goes well, though, and you're able to figure it out! If you do, post it here and I'll mark the thread as solved to help other people if they have the same issue.