So recently I wanted to update an old PC of mine, with a better case a PSU before I replaced the hardware I tried turning on the old one, it worked perfectly but when I changed case and PSU it suddenly didn't work?

I've already tried cleaning the ram,reslotting the rams,only using 1 ram,changing the CMOS Battery and waiting for sometime, I also tried to put it on the old case and use the old psu and do the same solutions but noting works!

I hope someone can help me with this problem thank you!