Receiving BSODs still after replacing several components. Any suggestions/ideas on what it could be?

Hi, all.

Been having a battle with BSODs for the last few months now. I'm not exactly loaded right now due to some personal circumstances so I've been slowly replacing components.

  • Replaced SSD (Crucial P1 to Samsung 990 Pro 2TB SSD). Relatively sure this was failing, was receiving tons of KERNEL_DATA_INPAGE errors on BSOD before, don’t recall having any since replacement, or maybe just 1.

  • Replaced CPU (AMD Ryzen 5600X, same model, new chip).

  • Replaced RAM (Corsair Vengeance 2 x 8GB 3200Mhz to ADATA XPG 2 x 8GB). These were confirmed as failing via Memtest, according to the repair guy I took it to. RAM would sometimes not be detected in certain slots, PC wouldn't POST with sticks in certain slots and wouldn’t turn on if PC was unplugged from wall after being shut down and attempted to boot back up, his replacements worked fine so I purchased those from him. Can confirm I no longer have these issues with the sticks I got from him, so he wasn’t scamming or anything. He's been a lovely guy aha.

Right now, I receive CRITICAL_PROCESS_DIED exclusively while gaming or benchmarking and even my repair guy is stumped. He has 0 idea what the problem is. We've tried DDU, 2 separate Windows installs, BIOS update, nothing has worked.

My remaining specs yet to be replaced are:

  • RTX 3080 FE.

  • Gigabyte B550 Aorus Pro V2 MOBO.

  • Corsair TX750M 80+ Gold PSU.

Surely one these have to be the issue here? Is there any chance that my replacement parts may have failed due to one of these being faulty?

Currently symptoms are:

  • PC will sometimes randomly reboot, no BSOD, goes to Gigabyte loading screen where I’m then booted into Windows log-in screen. Only while gaming.

  • CRITICAL_PROCESS_DIED BSOD. Can’t collect dumps as percentage stays at 0%. Does not occur during general use, just while gaming. Forced Windows to trigger one of these via Powershell and it collected the info fine, though, so I don’t think my replacement SSD is faulty.

  • Just the GPU switches off. All other components remain lit up, spinning and working (well, I think they’re working!). Only started happening yesterday, so not sure what caused this, haven’t been able to replicate today. One instance of this caused a 'Windows Couldn't Load Properly' after reboot, none after that.

  • Games seem to crash while loading. Ratchet and Clank: Rift Apart in particular during the portal sections does this sometimes.

Any ideas? I’m all out.