Hello everyone ! My first time writing on the site ,just signed up .And it is also my first time building a pc ! So here is what s up.I bought a prebuilt pc a couple of months ago (i5 4440 3.1 ghz ,8 gb ram , 2 tb hard drive ,gtx 660 ) .I was satisfied with the pc but i wanted a graphics performance and i bought a gtx 770 and it required a 600 w minimum psu so i went with the corsair rm 750w fully modular one.I saw some videos on how to do it but since it would be my first time i didnt want to risk doing some harm to the pc so i found someone online who claimed to be a specialist and did home visits and asked 35 pounds for replacing those two parts .What happened is that he came ,fited the gpu ,fited the psu and when he saw the cables for it he told me i would have to take it to another workshop to take a look at them'' in case curents are too strong for some ports ''(his words). so the next day i took the pc to another guys workshop and he told me it would take 4 days !!! can i have someones insight on the matter please ?sorry for the length and thanks for reading !cheers !