Pc still not turning on despite buying a new power supply

Can someone please help me? My pc stopped turning on but the “pwr led” light on the motherboard still came on. I thought it was a power supply issue so I bought a new one. I tried installing it and the same issue is occurring. I’ve never installed a power supply so maybe I did something wrong but I have it plugged into the cpu, gpu, and motherboard. Would it happen to be some other issue?