IDE cables shut down periferal

I see that this topic isn’t new but I haven’t found a post which actually aswers any questions asked. I’ve check all my connections and they are correctly connected, all the devices work individually from other sources, but on my new board the harddrive and cd rom drives do not work when the IDE cables are connected. I see others have solved there propblems and pted not to post how they were solved. I’m trying not to have to return the MOBO if I can.