New pc isn't working help me pls

[Rawr1]

Hi,

I just recently built a new computer using some older parts from a different pc. I had everything plugged in but I bought a psu that didn't work. I installed my old psu and the computer turned on (fans were running on case,CPU, and gpu) but nothing was working. I had no display, also the USB ports were not working properly. I would just like to know if anybody has an idea of what's happening or how I can fix it. Thanks

 

[Mankar Kameran]

Is there a graphics card or are you rocking integrated graphics?
It might just be the connection between monitor and pc.
The USB ports might not work until the computer downloads drivers for it.

 

[Rawr1]

Is there a graphics card or are you rocking integrated graphics?
It might just be the connection between monitor and pc.
The USB ports might not work until the computer downloads drivers for it.

I am using a graphics card but the drivers are already installed.

 

[Tradesman1]

Can you give a list of the components you are using?

 

[Rawr1]

Can you give a list of the components you are using?

I don't know what most of the components are because I got them from different bestbuy computers or from friends computers. The motherboard is asus and the graphics card is an msi r7770 but other than that really no info, sorry.