Not all MSI motherboards assign the power LED to pins 2 and 4. Review the manual included with your motherboard to determine which pins to connect the power LED connector to.

Motherboard won't start with power button - only with Green and Black cable ATX trick Cen100 Apr 21, 2010 Jump to latest Follow Reply ...

With a new Supplemental PCIe Power feature, some new MSI X870E ATX 3.1 motherboards have an extra connector to boost overall board power.

The power switch wiring cable is responsible for providing a connection to the Area-51's power button. The fan power bridge wiring ... Finally, the extra nuts provide compatibility for Micro-ATX ...