[SOLVED] Computer Soft-Crashing When Playing Games

[Jorvalt]

To provide a little bit of backstory, this all started when I swapped my GPU out for an old one because the current one's fans crapped out and I need to send it in for RMA.
For whatever reason, now my PC will just crash whenever I'm playing a game. Not a blue screen or just shutting off, but essentially everything except the PSU seems to turn off, as all of the fans but the PSU fans are off and the displays lose signal. The built-in LEDs on the motherboard stay on, though. After this happens, normally I can just hard reboot the PC, but sometimes it doesn't actually boot properly. I'm still not sure why, but again sometimes, not all the time, messing around with the RAM will get it to boot again.
So far I've tried running DDU (because I forgot to initially), resetting the BIOS, and running every test OCCT has. Despite the stress testing, it's only ever crashed when playing games. No idea why, as stress testing should achieve the same effect, right?
At this point I'm totally at a loss. No idea why this is happening, and it's becoming increasingly frustrating.

System specs:
GPU: Radeon RX 590
CPU: AMD Ryzen 5 3600 6-Core Processor
Motherboard: B450 Tomahawk MAX
RAM: 16 GB
PSU: Thermaltake Smart M750W

 

[rgd1101]

test with a different psu?

 

[Jorvalt]

test with a different psu?

If it was a PSU problem, wouldn't that have shown in the OCCT power test?

 

[mdd1963]

Some PSUs can pass every test, but, just not quite keep up the required voltages/currents required for a specific GPU...(there have been some that fail with some GPUs with lower overall power/wattage requirements, but, if it can't rapidly adjust to changing load, peak watts capabilities mean little...)

 

[Jorvalt]

Some PSUs can pass every test, but, just not quite keep up the required voltages/currents required for a specific GPU...(there have been some that fail with some GPUs with lower overall power/wattage requirements, but, if it can't rapidly adjust to changing load, peak watts capabilities mean little...)

As I said in the first post, this is a GPU that I had been using previously, with the same PSU. It should definitely be able to handle this one, especially since it was handling a higher end GPU for a long time before this. Unless it just now started failing, which is awfully convenient timing.
I really don't want to try swapping out PSUs unless I'm absolutely certain that the PSU is the issue, since it's both a pain and the only other one I have is older.

 

[Jorvalt]

test with a different psu?

Sorry for the late response. I just wanted to make sure that what I did actually fixed the problem. It turns out that the problem was in fact the PSU, as replacing it with another one I had caused the PC to stop crashing.