[SOLVED] Random PC crash (no bsod)

[pinheirom352]

Hello everyone! I hope this is in the right section.

I've had for very long time random crashes on my computer. I assumed they were due to a buggy instalation of windows back in the day but i have since changed a lot on my pc and they still happen!
It is very random , always during games , but i can never see a pattern. I can do a multi hour gaming session without problem ( even with GPU+CPU overclock) , and the next day with no OC it crashes on the first 15min of play.
I always monitor the temps and i am pretty sure overheating is not the problem

Upgrades:
from p8h77+i5 3350p to z97+i54690k+artic 33 and from win7 on a hdd to win10 on a new SSD
maintaining my old r9 390 and (this is the one im suspicious of) corsair green CX750.
I do have 2 sticks of non matching ram ( corsair vengeance 1600 and hyperx 1866 , but they match the frequency and should work with no problem i guess?)

The crash:
The screen goes black and the sound is frozen at the moment it crashes. The PC itself keeps running which is very strange

Could it be that my GPU is defective ? Not enough power from a weak psu?
Or software?( i use afterburner for gpu fan control etc altough its an asus strix)

PS Thanks!

 

[Supahos]

Best bet ram isn't playing nice. Mixing sticks is a crapshoot. Start by running memtest to see if it passes, one error is a complete failure

Next guess would be that aweful power supply. I wouldn't give it to someone I disliked even.

Then maybe gpu or defective used motherboard about a tie

 

[pinheirom352]

Thing is , i used to have only 1 stick and i *think* i still had the crashes but i will try to run memtest anyway. Would you believe i've had this PSU gaming everyday since 2014? I know its a bad one but it hasnt blown up my pc ... yet haha
If I upgrade , i would probably go for a seasonic s12ii 620 , i think it would a good choice for my 4690k+390 ?

 

[Supahos]

Yeah that's a pretty good fit. It's not the worst unit in the world (750cx) but it doesn't suspect caps, the only thing that makes it better than the complete junk ones is it's built well enough it doesn't usually take everything else down with it.

 

[pinheirom352]

Did 3 complete passes on memtest86 with 0 errors. Well i'm very inclined to the psu , is there any test to guarantee its not the gpu causing the problem?

 

[Supahos]

Playing without the GPU I suppose. If it still crashes it can't be the GPU. But even if it doesn't crash it still could be the power supply

 

[pinheirom352]

Especially because its a power hungry GPU , if i tried with a 1060 my neighbour has i probably wouldn't be able to replicate the issue :/ oh well , ill get the new psu and try it out.
Thank you supahos