So you have tested everything from the motherboard to the floppy drive. Still having problems? Have you tried testing the power supply? This Daily Drill Down by Faithe Wempen gives you the scoop on ...
When attached to a motherboard's PCIe x16 slot, a card such as the GeForce RTX 4080 can draw up to 75W from the +3.3V and +12V rails (3.3V x 3A + 12V x 5.5A). This is the maximum amount specified by ...