Losing Internet connection after 15 minutes?

So after upgrading my mother board I started to experience a strange issue; Im losing my internet connection after aprox 15-20 minutes with limited internet icon and cant get ip error. All other computers are fine wired and wireless. Here are the steps I took to troubleshot the problem:

Change the cable

flush /renew ip

put the pc on high performance mode

Restart my router

Format my PC back to Windows 8

The only way to get the internet back on is by unclogging the power cable for 10 minutes and reconnecting it. After 20 mins the problem comes back. I have never experienced this before on my windows 8 so I formatted back from my newly installed windows8.1 but same thing. I believe I started to smell smoothing around the power supply but Im not sure.

Smell aside, can the power supply cause this? I need to know for sure before I go out and get anew cooler master.

Thanks