System freezes not certain pattern

[Martin1982]

I build a system for friend it is kinda unstable it is not overcloked.
His system will suddenly freeze sometimes within 10 min sometimes 3 hours
all temps er good, and this error happens without any certain patteren. gaming, browsing, youtube

System
MB: GA-970A-UD3
Ram Kingston hyper x 1866 2x4 gb
Gpu Gigabyte R9 280 3 gb
Cpu Amd fx 6300
Psu Cooler master 600w

OS win 7 64 bit

I think it might be a bad MB but im not sure.

 

[brispuss]

Intermittent faults can be difficult to locate.

First, check that ALL cables are connected properly (power, data, monitor). And ensure video card and DIMM's are seated properly.

Second, remove CPU and check CPU socket for damaged/missing pins, and check there is no damage to CPU pads. Re-seat CPU and CPU cooler carefully and evenly. Don't over tighten cooler mounting screws.

If problems continue, try swapping DIMM's with each other, and/or try different slots.