I have this computer that I used before the one that I am currently using, and I did some wierd shit to it before. for some ungodly reason, and now I can't get it to work. As far as I know everything works (as in isn't broken), however when I plug a ribbon cable into the CD drive or the HDD then it doesn't power up, but if I take out the ribbon cable then it powers up. I think it might be a PSU problem but I don't know. I should have the HDD's set up with the master/slave shit correct and the CD drive set up correctly, but it still doesn't work. I've checked out guides and I believe I am doing it right but it isn't working.
TL;DR:
This old computer isn't working and when I leave the ribbon cable in any component (except the floppy) it doesn't power up, but if I take the ribbon cable out it powers up fine.