If they are powered risers, you have to attach the molex to the psu or they will not work at all... I'm not sure how your mobo is designed, but I would attach the psu's peripheral power molex connectors straight to your powered risers.
It's working thanks you, i feel dumb to not have tried this before, but since the mobo had the molex to power the gpu i did it wrong, send me your ltc add in pm btw
Also make sure you plug the PCI-E adapter in the correct way. If you do it incorrect it will burn the PCI-E slot. I've seen it happen to a few customers