I work these often and we begin with a good cleaning, new heatsink compound (as the owner tells us it's not heat) all around including the North and South bridge chips. All connections and boards are unplugged one at a time and plugged back in. Any fan that doesn't work like new is replaced.
Now it's retested. If it fails we swap out the PSU and maybe the GPU then retest. Most homebuilders don't have spares so many have to go with "replace the cheapest part first."
Recently I have been having this problem when my pc shuts down randomly not only when gaming but even when nothing’s loaded up. I want to say it’s my power supply because when it shuts down everything loses power including the gpu and mother board. When it shuts down it turns back on by its self but sometimes it won’t even load into window and will run me into errors like windows couldn’t load correctly or your pc has ran into a problem.
My specs are
Intel i7 2600
Gtx 750ti
8gb ram
Corsair tx650m psu
500gb of storage
Windows10
Anything helps, thank you.

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