USB Ports aren't working and isn't showing on monitor when turned on

ImStyles

Commendable
Dec 11, 2016
2
0
1,510
My water cooling wasn't working in my computer so I went to take it out and replace it with a default cpu fan. After putting the fan in and getting everything fixed I put the computer back together and now whenever I turn my computer on it turns on for a second and then turns off for a second then I have to press the power button again for it to fully turn on, my monitor keeps saying "HDMI No Signal", and none of my USB ports are working, neither the ones on the case and the ones on the motherboard. Can someone tell me what I will have to replace? I think it might be the power supply or the motherboard but I would like to get a second opinion. Thanks