If I am not wrong the powersupply of the mobo is located under the drivers board. With long cable, bound togeather. Try to find another place. And maybe that has hot too and got older... More sensitive to emv.
P. S.
I place ferrites in my drivers cables and also use shielded cables for such connections. With earth on both sides as for me hf shield is more important than low frequency shielding.
Mike
