PC boots but there is no power to USB or display

[wildpack.jack]

My pc turns on but no display or power to USB devices, I can fix it by resetting the CMOS but when I put my side panel back on the display turns off again followed by the usb losing power.
I have no idea how to fix it. It had been working for over a year but a month ago I replaced the psu so it might be my poor wiring as the GPU requires an 8pin and 6pin connection and it causes the wire of the PSU to stick out of the case a bit.

Thanks.

 

[Ralston18]

Make and model GPU?

Update your post to include full hardware specs and OS.

And be sure to include make and model information for both the old and new PSU.