Pc shuts down after 30 mins.

[Joecake]

My pc had some weird issues recently, was working perfectly fine but one day i turned on my pc and my ethernet port died and at the same time my pc shuts down every 30 mins, so i got a lan card but the slots in my motherboard dont work for some reason as if the are dead and my motherboard cant recognize them ,so i got a usb lan to connect to the internet and it works but still pc shuts down so i went on and started to hunt down the issue but alot of threads online claiming the soulution that they all switched thier motherboards and now everything is fine , also here is what i tried , re-installed windows / took out motherboard battery and unplugged the power cable (to release all electricty) and before that i rolled back windows update and restored and still nothing works , i switched the ram placments around cleaned all the dust yet nothing ,still 30 mins. Is all i get ,sorry if my english is bad but some1 plz help , i use this pc for work and gamming , intel i5 4670 , gtx nvidia 770 4gb , 2 tb harddrive and a gigabyte z87x-d3h mother board , your help is much appreciated 

[GtaSeriesFan]

Faulty motherboard,CPU,PSU ? May be a wide guess but most likely 1 of these 3 is faulty, may suggest swapping a psu (ask a friend) and see what this does. Motherboard is half dead i suppose that's where the problem is , but why did it get damaged may be due to a faulty PSU. 

[GtaSeriesFan]

Also the cmos battery could be dead, and can cause the pc to shot down. Wild guess

[Joecake]

9 minutes ago, GtaSeriesFan said:

Also the cmos battery could be dead, and can cause the pc to shot down. Wild guess

True but if i ctrl alt del and open processes it shows the uptime and it never reaches 30mins as soon as it hits or passes 29 mins the pc shuts down i checked temperatures and all is normal