Can a PSU kill USB ports?

[koneko neko]

Hello everyone need some help. Today I come home to my brother telling me this Pc wont recognize any of his usb devices. He has his mouse, keyboard and his WiFi running on usb. I started trouble shooting and all Mobo usb and the front panels are not working. I added in a pcie usb 3 card I had to give that a go. It worked on first boot. But after a restart it stopped giving power and everything to my mouse. I reseated ram. Tried different ram slots . Even reseated the cpu and remounted the cooler. Nothing worked. So the last ditch thing I did was I sawapped in a old psu i had that is enough to just to get the system to boot without the gpu installed . The pcie card was giving power and i could use everything in windows. It also worked threw reboots. Now the usb on the mobo did not come back so i am still not completely sure if the psu is the issue or the mobo.  The psu in it is a 600w Evga one that was bought less then a year ago. Any help would be appreciated. 

 

Thanks