How To Install A PCIe Power Plug Into An Older Computer PSU

How to fabricate a pcie converter adapter into an older power supply with only standard 4 pin molex legacy power output. I got an old computer that had a faulty psu, and the only working power supply I had only had the molex style plugs. I needed a pcie plug for the graphics card, so a integrated one into the old psu. Wiring diagram for the retrofit is at the beginning of the video.