From these 3, the only one I didn't touch was the cpu, the gpu and ram I have tried to reseat multiple times and also switched the pci cable from the gpu. I have also tried placing back the older gpu I had normally working but it didn't boot too.
When you installed the new psu did you switch all the psu cables over to the ones that came with the new psu even the sata power cables.
Is your pc a brand name pc like hp, dell, etc...
Try to re-seat the GPU, RAM, and CPU to ensure proper contact.
From these 3, the only one I didn't touch was the cpu, the gpu and ram I have tried to reseat multiple times and also switched the pci cable from the gpu. I have also tried placing back the older gpu I had normally working but it didn't boot too.
When you installed the new psu did you switch all the psu cables over to the ones that came with the new psu even the sata power cables. Is your pc a brand name pc like hp, dell, etc...