A power supply unit (PSU) mismatch detection system that includes a plurality of PSU slots configured to couple to a PSU and transmit power to an auxiliary power rail (APR) and a main power rail (MPR), a controller that is coupled to the MPR and the PSU slots and configured to perform a PSU mismatch check on each PSU coupled to the PSU slots, and a programmable logic device (PLD) that is coupled to the APR, the MPR, and each of the plurality of PSU slots. The PLD enables transmission of power to the MPR from a first PSU coupled to a first PSU slot, receives an indication that the controller has completed the PSU mismatch check, determines valid PSU slots using the results of the PSU mismatch check, and enables the transmission of power to the main power rail from the valid PSUs slots.