Alienware Aurora R7 Power issues

Hi. I have purchased an alienware aurora R7 last year and it worked fine until this past October. Then when I power it on and shut it down I would come back to it later and it may or may not turn on. Now it's at the point where it wont power on at all. I have tried replacing the power supply and that did not fix the issue I also replaced the CMOS battery in the motherboard and still no fix. any suggestions?? 

Thanks in advance