![ROFL :ROFLMAO: :ROFLMAO:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Joke of the day.
OCing Athlon 3000G is 1st for me.
If you have no idea what is going on, then why do you confuse OP even more?
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This does:
Why?
Your PSU is low quality PSU and not suitable to be used with any PC.
Random reboots or shutdowns are mostly caused by 2 issues:
1. CPU/GPU overheats and to prevent any damage, system shuts down.
2. PSU fails to deliver enough power to the GPU or fails to keep smooth enough voltage for PC's operation.
Since your temps are within reason, it's the PSU who is acting up.
While your PSU has enough wattage for your system, your PSU is low build quality and i'm pretty sure that it's voltage regulation has sifted outside of the ATX PSU standard specs of 5% on all rails (10% on -12V and -5V rails) and your PSU can't sustain stable enough voltage for your 75W GPU to run under higher load. That's why your PC shuts down once you start gaming.
Only fix is new, good quality PSU. E.g Seasonic Focus or Corsair RMi/RMx, in 550W range.
For 2nd opinion about your EVGA unit, look PSU tier list, under Tier C,
link:
https://forums.tomshardware.com/thr...er-list-rev-14-8-final-update-jul-21.3624094/
While what i suggest getting (and am also using myself), would be anything from Tier A.
Everything that is connected to PSU. <- This is the price you have to pay, when you cheap out on PSU. Since PSU powers everything, it is
the most important component inside the PC. And you do not want to cheap out on PSU, if you care about your hardware.
Why now? Well, your cheap PSU, most likely, fed out of spec voltages to your hardware, damaging them over time. Until to the point where there is real life issues with the PC.
You can look it like getting a car tire punctured by a nail. Once there is small hole in the tire, tire won't go flat at an instant. Instead it will gradually loose air, until it completely deflates, at which point you can tell that you have a flat tire (rumble noise while driving, poor turning etc).
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At this point, your next course of action would be buying brand new, good quality PSU. Once you have new, good quality PSU installed, look if you still have your issues.
If not, great, you got lucky and can enjoy your PC easy 10+ years (the normal lifespan of good quality PSU).
If you still have your issues, despite using brand new, good quality PSU, then this means your cheap EVGA PSU damaged your hardware. MoBo is usually 1st one to give up the ghost, followed by GPU close-by. This means hardware replacement, since there is no way to "fix" damaged MoBo/GPU.