Strange power on issue with continious fan

[ATLANT3AN]

Hey there, I took my graphics card out of my QX9450 to put into my new Coire i7 rig as I have not got my new GC yet and then put it back, When I switched on the PC you could just hear the fan spinning loudly continuosly, usually it does it for a few seconds then stops and shows BIOS. The little attachment was stuck at DET DRAM. Now when I fiddled with the PCI power to the GC it worked but then when I moved my tower back under desk it did not. I opened it up again moved the pci-e power wire a little bit and tucked it behind another cable, the same thing occured; it worked then did not. In the end moving the main motherboard power socket to a slightly different location made this work on the next boot and from there on hence me posting here.

I have had this exact same thing happened before and it was due to the GC power not being connected. But with moving some cables other than this only slightly fixing it, I am confused. Any thoughts?

ATLANT3AN