pc turning off after 5-10 mins. I don't think it's psu or overheating.

[joshsettle]

Ok basically about 2 months ago my Pc broke and a transistor or something broke on my motherboard.
Fast forward to today and I'm replacing my motherboard. After replacing it and Settin up it seemed to be working fine for the first 7 mins. Then all of a sudden it just powers off.
I don't think it is a problem with overheating because it has been running at sub 25 C all day (according to temp monitor on case).
I tried to test if it was a motherboard issue by trying to run it without my graphics card to reduce power demands but the same issue persists.
So by reading other threads the main solutions seem to be clean your pc or get a new psu. But I really don't think either of these are my problem so does anyone have any advice on what's going on/what to do?
Any help is appreciated - Josh

 

[norsestar]

What PSU (make and model) do you have? What are the rest of your system specs? Random shutdowns are often power supply related...

 

[joshsettle]

What PSU (make and model) do you have? What are the rest of your system specs? Random shutdowns are often power supply related...

PSU: Corsair cmpsu-550vx
CPU: AMD FX 6300
GPU: AMD 7850
motherboard: m5a78l-m/usb3

btw its not random shutdowns. its a persistent every 5-10 mins every time i turn on the PC.
Do you think this could be related to incorrect application of thermal paste? cuz im not sure exactly what my case temp monitor reads :/

 

[TonyRoma]

Use HWinfo64 for monitoring your temperatures, it will be far more accurate than the temp display on your case which probably uses a thermal probe. It might also we worth removing your CPU and double checking it is installed correctly with no bend pins (AMD, handle with great care!) and no damage to your LGA socket (Intel). Regarding your thermal paste, you only apply a small amount. Its purpose is to remove any air pockets and give good contact to the heatsink. So don't go at it like you're icing a cake. Once you've established it is installed correctly and still persists in shutting down, it might be worth while trying another PSU if it's available to you. Good luck, be patient with it.